verb

act dishonestly or unfairly in order to gain an advantage.

she always cheats at cards

noun

a person who behaves dishonestly in order to gain an advantage.

swindler,cheater,fraudster,trickster,confidence trickster,deceiver,hoaxer,hoodwinker,double-dealer,double-crosser,sham,fraud,fake,crook,rogue,charlatan,quack,mountebank,racketeer,con man,con artist,shark,sharper,phoney,hustler,flimflammer,flimflam man,twister,grifter,bunco artist,gold brick,chiseller,shicer,magsman,illywhacker,schlenter,confidence man,confidence woman,defalcator,tregetour