shark

1 a dishonest person who uses clever means to cheat others out of something of value a card shark Synonyms bilk, bilker, cheat, cheater, chiseler (or chiseller), confidence man, cozener, defrauder, dodger, fakir, finagler, fraudster [chiefly British], hoaxer, scammer, scamster, trickster, sharper, sharpie (or sharpy), skinner, swindler, trickerRelated Words double-crosser, double-dealer; bluffer, charlatan, fake, faker, humbug, impostor (or imposter), mountebank, phony (also phoney), pretender, quack, quacksalver, ringer, sham; adventurer, fox, gamesman, knave, prankster, rascal, rogue; fast-talker, slick, slicker, slickster, slyboots, smoothy (or smoothie), wheeler-dealer; plotter, schemer, sneak, sneaker; blackleg, cardsharp (or cardsharper)

2 a person with a high level of knowledge or skill in a field a shark at calculus Synonyms ace, adept, artist, authority, cognoscente, connoisseur, crackerjack (also crackajack), dab [chiefly British], dab hand [chiefly British], fiend, geek, guru, hand, hotshot, maestro, master, maven (also mavin), meister, past master, proficient, scholar, expert, sharp, virtuoso, whiz, wizardRelated Words pro, professional; consultant, hired gun, specialist; addict, aficionado (also afficionado), buff, devotee, enthusiast, fan; craftsman, journeyman; all-rounder [British], jack-of-all-trades, Renaissance man; mistressNear Antonyms apprentice, beginner, neophyte, novice; dabbler, dilettante; layman, nonprofessionalAntonyms amateur, inexpert, nonexpert

3 a person who habitually preys upon others being a new arrival in Hollywood, she was easy prey for the sharks in the movie business Synonyms bloodsucker, buzzard, harpy, kite, predator, vampire, vulture, wolfRelated Words exploiter, user; leech, sponge, sponger; destroyer, devourerAntonyms prey