Booby

Booby (pronounced boo-bee)

(1) A bird, a gannet of the genus Sula, having a bright bill, bright feet, or both; some are listed as threatened or endangered.

(2) A slang term for someone thought stupid or a dunce, ignorant or foolish (although still used in the mid-twentieth century, it's probably now obsolete, the meaning crowded out by intrusion of newer slang, some of which has also fallen victim to the linguistic treadmill).

(3) The losing player in a game (historic UK usage as "booby prize", now largely obsolete except in informal use).

(4) One of the many slang terms for the human female's breasts and related to the more common boob, boobs and boobie.

(5) In croquet, a ball that has not passed through the first wicket. 

1590s: From Spanish Latin from the earlier pooby, apparently a blend of (the now obsolete in this context) poop (to befool) and baby, perhaps by association with Spanish bobo (stupid person, slow bird), thought to be from an imitative root of the Latin balbus (stuttering).  Balbus was from the primitive Indo-European balb- & balbal- (tongue-tied) and was cognate with the Ancient Greek βαμβαίνω (bambaínō) & βαμβαλύζω (bambalúzō) (I chatter with the teeth), the Russian болтать (boltatʹ) (to chatter, to babble), the Lithuanian balbė́ti (to talk, to babble), the Sanskrit बल्बला (balbalā) (stammering) and the Albanian belbët (stammering).  The booby prize dates from 1883, a prize given to the loser in a game as concept which persists in some sporting competitions as "the wooden spoon", the idea being something as removed as possible from the usual silverware given as trophies.  The booby trap was first noted in 1850, originally a schoolboy prank (ie something only a "boob" would fall for); the more lethal sense developed during World War I and remain common military and para-military use.  Booby and boobyism are nouns, boobyish and (the non-standard but potentially useful)  boobyesque are adjectives; the noun plural is boobies.

Found usually in pairs

A nice pair of boobies.

A booby is a seabird in the genus Sula, part of the Sulidae family. Boobies are closely related to the gannets (Morus), which were formerly included in Sula, the genus created in 1760 by the French naturalist Mathurin Jacques Brisson (1723-1806).  The name is derived from súla, the Old Norse and Icelandic word for the other member of the family Sulidae, the gannet.  The English name booby was based on the Spanish bobo (stupid) as the tame birds often landed on board sailing ships, where they were easily captured and eaten.  As well as a popular addition to the diet of sailors for whom meat other than fish was a rarity, it was fortuitous for many, the Admiralty's archives revealing boobies are often mentioned as having been caught and eaten by shipwrecked sailors.  In taxonomic classification, variations include Abbott's booby (Papasula abbotti), blue-footed booby (Sula nebouxii), brown booby (Sula leucogaster), masked booby (Sula dactylatra), Nazca booby (Sula granti), Peruvian booby (Sula variegata), red-footed booby (Sula sula) & Tasman booby (Sula dactylatra tasmani).

Boobies in time, in step.

Based on the use by mainstream internet sites (including nominally reputable news organizations), boob (more commonly in the plural as boobs) seems to have emerged as the preferred slang for breasts, probably because it seems the term women find most acceptable and the one they most often use, not infrequently as their default descriptor.  The origin appears to lie in bubby (plural bubbies), a slang term for the female breast dating from the 1680s which is thought to be imitative of a baby's cry or the sucking sound heard during lactation.  It was most associated with south-east England although that may reflect more extensive documentation rather than proof of regionalism.  Inherently anyway a form in oral use, the alternative pronunciations included buhb-ee, boo-bee & boob-ee so the evolution to boob was perhaps not unexpected although most dictionaries list the earliest known instance as a late 1930s Americanism with the back-formed clippings boob & boobs not appearing until the early post-war years, initially as a vulgarism, women not embracing use for decades although that their approval seems to have coincided with late second-wave feminism is presumably coincidental.

Fully loaded: Lindsay Lohan in boobie-top with crash helmet, Herbie: Fully Loaded (2005).

In fashion, the boobie top (less commonly as booby-top) is a style of clothing (including dresses) which in some way draws attention to or emphasizes the breasts.  The design is most associated with generous displays of cleavage or skin but is used also to refer to garments which wholly cover the breasts in such as way as to highlight the size, shape or movement.

During World II (1939-1945), the US military kept up with evolution of slang, something reflected in advertising which lent a new definition to "booby trap", a familiar concept in which soldiers were well-drilled.  Until well into the twentieth century (and the beginning of the antibiotic era), it wasn't unusual for the losses of combat-ready troops to illness & disease to exceed those caused by battlefield causalities and although the numbers were dwarfed by conditions such a malaria, preventing and treating sexually transmitted diseases (STDs, then called venereal disease (VD)) was an important component of military medicine.