cutthroat UK /ˈkʌtθɹəʊt/US /ˈkʌtθɹoʊt/adjective 3noun 4forms 3 adjective3 •Involving the cutting of throats. •Ruthlessly competitive, dog-eat-dog.Law is a cutthroat business, you always have to look out to see who is trying to outdo you. •Of or relating to a card game where everyone plays for him or herself rather than playing with a partner.He found that playing cutthroat Spades was much more difficult than playing with a partner. noun4 •A murderer who slits the throats of victims. •An unscrupulous, ruthless or unethical person. •A three-player pocket billiards game where the object is to be the last player with at least one ball still on the table. •Ellipsis of cutthroat compound (“an agentive-instrumental verb-noun compound word”).Children go through a phase of compound acquisition in which they invent cutthroats spontaneously before dropping the habit again. — 2015 formscutthroats · more cutthroat · most cutthroat