Cutthroat

Cutthroat (pronounced kuht-throht)

(1) Slang for a murderer (regardless of chosen method) or one thought capable of murder.

(2) Ruthless in competition.

(3) In games of cards where the rules permit each of three or more persons to act and score as an individual.

(4) In billiards, a three person game where the object is to be the last player with at least one ball still on the table.

(5) The Cutthroat eel, a family, Synaphobranchidae, of eels found worldwide in temperate and tropical seas.

(6) The Cutthroat trout (Oncorhynchus clarkii), a species of freshwater fish in the salmon family of order Salmoniformes.

(7) The Cutthroat finch, a common species of estrildid finch found in Africa.

(8) The Cutthroat razor, a reusable knife blade used for shaving hair.

1525–1535: A compound word: cut + throat.  Cut (1175–1225) is from the Middle English cutten, kitten, kytten & ketten (to cut), from the Old English cyttan (related to the Scots kut & kit (to cut)), probably of North Germanic origin, from the Old Norse kytja & kutta, from the Proto-Germanic kutjaną & kuttaną (to cut), of uncertain origin, perhaps related to the Proto-Germanic kwetwą (meat, flesh). It was akin to the Middle Swedish kotta (to cut or carve with a knife), the Swedish kuta & kytti (a knife)), the Norwegian kutte (to cut), the Icelandic kuta (to cut with a knife), the Old Norse kuti (small knife) and the Norwegian kyttel, kytel & kjutul (pointed slip of wood used to strip bark).  Descent from the Old French coutel (knife) is thought improbable.  It displaced the native Middle English snithen (from Old English snīþan (related to the German schneiden)), which still survives in some dialects as snithe.  Throat (pre-900) is from the Middle English throte, from the Old English throtu, þrote, þrota & þrotu (throat), from the Proto-Germanic þrutō (throat), from the primitive Indo-European trud- (to swell, become stiff).  It was cognate with the Dutch strot (throat), the German drossel (throttle, gorge of game (wild animals)), the Icelandic þroti (swelling) and the Swedish trut.  The Old English throtu was related to the Old High German drozza (throat) and the Old Norse throti (swelling).

Words with a similar meaning, include ferocious, vicious, savage, barbarous, bloodthirsty, cruel, dog-eat-dog, merciless, pitiless & relentless, unprincipled.  The alternative form is cut-throat although dictionaries note the rare use of cut throat.  Cutthroat is a noun & adjective; the noun plural is cutthroats.

The cutthroat trout (Oncorhynchus clarkii) is of the family Salmonidae and is native to a number of North American cold-water tributaries of the Pacific Ocean and Rocky Mountains.  The common name "cutthroat" is derived from the coloration on the underside of the lower jaw.