Demi- (pronounced dem-ee or dem-ahy)
Of less
than full size, status, or rank.
Circa
1350s: From the Middle English demi
(half, half-sized, partial), from the twelfth century Anglo-Norman demi (half), from the Vulgar Latin dimedius, from the Classical Latin dīmidius, the construct being dis- (apart; in two) + medius (middle). The French demi which English borrowed was a combining form which existed as
noun, adjective, and adverb. It appears
in loanwords from French meaning “half” (demilune),
“lesser” (demitasse), or sometimes
used with a pejorative sense (demimonde)
and, on that model, is also prefixed to words of English origin (eg demigod).
Hemi- (pronounced hem-ee)
A
combining form meaning “half,” used in the formation of compound words (eg
hemispherical, hemimorphic, hemicardia et al).
Pre
900: From the Middle English hemi from the Ancient Greek prefix ἡμι- (hēmi-)
(half), from ἥμισυς (hḗmisus) (half).
It was cognate with the Classical Latin sēmi- and, as a word -forming element meaning "half", was
a Middle English borrowing from the Latin hemi- which was taken directly from the
Greek hēmi- (half) from the primitive
Indo-European semi-, source also of
the Sanskrit सामि (sāmí), the Old High German sami- (half) the Old English sam- and others, all soon denoting a
partial or imperfect condition as well as the classically correct “half”.
Semi- (pronounced sem-ee)
(1) Half
(strictly speaking) as in “semicircle”.
(2) In
informal use, a proportion of something less than the whole.
(3) In
English, a combining form or prefix (sometimes hyphenated) appended to words of
any origin, usually with the senses of “partially,” “incompletely” or “somewhat”
(eg semi-final, semi-trailer, semiautomatic, semi-articulated, semi-detached et
al).
1400s: From the Middle English semi, from the Latin sēmi-
(half). It was connected with the Old
English sōm- & sām- (half) (and related to the modern dialectical
sam-), the Old High German sāmi-, the Sanskrit सामि (sāmí) and the Ancient Greek hemi-. Ultimate root was the primitive Indo-European
sēmi.
The word-forming prefixes semi-, hemi-, and demi- all began life meaning “half” but have evolved to mean other things too and exist also not just as prefixes but as stand-alone forms. As a prefix, there appears to be 951 words with a “semi-” prefix, around 215 with a “hemi-” while a “demi” is appended only to 172, and, although it’s never been a rule, because of the origins, “demi-” is probably best paired with words of French origin, whereas “semi-” is a more natural fit with words with a Latin root.
Semi- may refer to something happening more than once (usually twice) within a certain time and is probably most familiar as “semi-final” to describe the matches of a competition which will determine the finalists. In English it was used first to mean “half but became soon attached to concepts impossible to quantify (eg semi-abstract; semi-permanent) and thus came to mean also “virtually” or “somewhat.”
Hemi- is often employed in the hard-sciences. It’s less commonly used than semi-, the association with the technical language of fields such as physics, chemistry, mathematics, biology and anatomy tending to mean it’s applied with more exactitude but even here, practices of use have produced anomalies. In general use, it’s perhaps best known as a descriptor of the shape of the combustion chamber of certain internal combustion chambers to the extent of “Hemi” the noun being a Stellantis (the holding company of which Chrysler is now a part) trademark, even though many of the engines the company now market as such use a different shape.
Lindsay Lohan in underwired demi-cup bra, photoshoot by Terry Richardson (b 1965) for Love Magazine, 2012. The "demi-cup look" can be achieved by choosing a bra with the correct band size and a smaller cup. Someone who usually wears a full-cup 32D would use a 32C or even 32B to get the effect although, given the variation in cup shapes between manufacturers, some experimentation will likely be required and fitters caution this should be done in a physical store rather than shopping on-line.
The demi-cup style is most associated with the “push-up” bra of which Playtex's Wonderbra is the best known. As the name implies, a demi-cup bra is one where the fabric covers rather less than the mainstream “full cup” bra although not necessarily half, some more revealing than others and the demi-cup is designed better to display the cleavage but need not do so in the exaggerated manner of the push-up bra, almost all of which use a kind of demi-cup. Many demi-cup bras don't use the push-up engineering though they typically include most of the familiar components (padding, underwires etc). A variation of the demi style is also inherent to the “plunge bra”, designed to accommodate garments with a low cut but why the industry settled on demi-cup rather than semi-cup isn't known and the term isn't universal, some manufacturers preferring "half cup". Still, it's definitely all about the cup and to be regarded as a demi bra, it should be constructed with partial cups which cover between 50-75% of the breast and coverage should be the same all across the bra (similar to a balconette bra) as opposed to Plunge or T-Shirt bras where there's a slight dip in the middle. Additionally, most demis use an underwire in a slightly wider than usual U-shape, evenly arched.
Demi- is used suggest something of less than full-size or status although it doesn’t of necessity imply something inferior. In English, it’s the rarest of the three forms and, in English, was first used in heraldry, where things like demi-angels, demi-lions, demi-horses were applied to escutcheons. It also held sway in certain niches such as the military (demi-brigade) and fashion (demi-cap; demi-lustre; demi-worsted) and coach-building (demi-limousine). Of late, it has absorbed the sense of “virtual” as well as “lesser” and is quirky too: A demigod, while certainly not quite the real thing can be applied with either negative or positive connotations.
1969 Ford Torino Talladega.
Although modest by comparison with Chrysler’s radial Daytona and Superbird, Ford’s aerodynamic enhancements to the Torino proved surprisingly effective. Actually, so good was the Talladega that when the sleek-looking replacement was released, the racers found it was slower and kept their Talladegas in service as long as they were eligible. Ford had produced enough of their Fairlane-based Torino Talladegas to run them on the NASCAR circuits but needed to sell five-hundred cars with their new BOSS 429 V8 engine to reach the homologation threshold.
That was also bad because the Boss 429 was a big lump designed to fit in the wide-bodied intermediates and such was the task to shoehorn it into the narrower Mustang that the job had to be out-sourced to a specialist contractor because inserting the labour-intensive programme into the highly-structured Ford production-lines would have been too disruptive. Thus, cars were delivered to the contractor which also received the 429 engines in crates. Destined originally to be fitted with the physically smaller 428 SCJ engines, it was no small task to make the 429 fit, the shock towers being moved outwards along with the upper and lower control arms and stiffer springs were fitted and, surprisingly, it actually worked out quite well. Although the bulky heads made the 429 a wide piece of machinery, they were made of aluminum and the total package was barely heavier than the all-iron 428 and some even included a few magnesium components which were lighter still. The changes made had the effect of moving the front wheels further apart and increasing their negative camber and this gave the Boss 429 the best handling and road manners of any big-block Mustang although, it was still a front-heavy thing and clumsy to drive at low speed. Re-locating the battery to the boot helped weight-distribution a little but none of the changes were ever going to make it behave like a Lotus Elan.
1969 Ford Mustang Boss 429.
However, one implication of things being such a tight fit was that there wasn’t the space to fit a free-flowing exhaust system so in the Mustang it was never possible for the engine to breathe as deeply as it did in the big NASCAR stockers and knowing this, Ford made no attempt to configure the it for maximum output, the carburetor smaller than those used on the Boss 302 and Boss 351. Nor were the internal components assembled in a specification consistently intended to maximize performance, some built (supposedly in error) with a valve train which limited engine speed and the project anyway was a homologation exercise designed to sell the requisite number of parts required to qualify them for competition although, despite the low production spread over only two years, there were three distinct variations. The first few hundred (S-code) units used heavy connecting rods secured with ½ inch (13 mm) bolts whereas the rest of the 1969 run and most built in 1970 (T-code) were fitted with lighter pieces and ⅜ (9 mm) bolts and initially, the early T-code engines carried over the hydraulic lifters from the S-code but production soon switched to a solid lifters with a somewhat more lumpy camshaft, the magnesium valve covers at the same time replaced with units cast in aluminum. Finally there was an edition (A-code) which appeared in the last few of those built in 1970 and it varied from the T-series specification only in in some changes to the plumbing associated with what was still a quite rudimentary anti-pollution system. Whatever its variations, a Boss 429 Mustang was what it was.
The shotgun ports.
It was also what it was not. Expectations were high and, on paper, not unreasonable because the notion of putting a genuine seven litre racing engine in something as (relatively) small as the Mustang did hint at something special but, with the strangled engine, although quick, it wasn’t a cataclysm on wheels and the opposition was quicker still. One of the issues was the fundamental design of those exotic heads. Nick-named shotgun because the intake and exhaust ports reminded many of the double-barrels of a 12-gauge (although each was large enough almost to swallow a tennis ball), they worked admirably in the Talladegas at high-speed where they were matched with a big carburetor and free-flowing exhaust system. On the street however, the big shotgun ports rarely saw sustained high-speed running and their sheer size meant the fuel at low speed didn’t achieve the flow-rate necessary for the low-end response needed on the street or strip.
1969 Boss 429 on stand with open exhaust headers.
Prior to release there was talk of quarter-mile runs somewhere in the twelve second range but in reality, no stock Boss 429 ever went quicker than low fourteens, enough to put it in the upper echelon of the muscle car era but there were those who expected more. More did come, as initially disillusioned engine builders began to understand what it responded to, it became for decades one of the dominant forces in drag-racing, the shotgun ports meaning it took to forced aspiration like few engines, twin-turbocharged Boss engines able to generate thousands of horsepower.
1970 Ford Mustang Boss 429.
So it was quite a legacy and the surviving Mustangs now sell for as much as US$250,000. Although Ford was compelled to build only 500, 857-odd were sold in 1969 and 499 in 1970 so it’s a bit of an oddity, quite a rarity yet almost mass-produced compared with some of the limited production machines of the muscle car era and such is the allure that there are companies now producing reproductions of the famous heads, modified slightly to fit regular production blocks. It’s never been known how much money Ford lost on each Mustang it sold but, fitted with the famous Holley Dominator 1150 CFM carburetor and open exhaust headers suited to an engine happiest running at full throttle, the BOSS 429 did its job on the circuits and the company seemed happy with the investment although its life as a flag-bearer would be short, motorsport soon to be neglected as a changing world and a onrush of legislation demanding compliance needing the resources the circuits soaked up.
The semi-hemi combustion chamber.
As well as being nick-named the shotgun, it was also called the semi-hemi. The BOSS 429’s combustion chambers weren’t actually hemispherical but they tended towards the shape (and the ones used in the race cars sometimes were). Although Ford apparently would have preferred to have them known as a "blue crescent", it didn't catch on and, there being no obvious word in use to describe what they looked like, they came to be known as semi-hemi. Musicologists had already gone one better than Ford. Noting that English had contrived to borrow three words from Antiquity in order to have three prefixes meaning “half”, they invented hemidemisemiquaver to describe a sixty-fourth of a note (ie a half of a half of a half of an eighth note), a coining from that year of semi-revolutions: 1848.