Synonyms and related words :
amoral, artful, back-door, backstairs, calculating, chiseling, clandestine, collusive, conscienceless, corrupt, corrupted, covert, covinous, crafty, criminal, crooked, cunning, dark, deceitful, devious, dishonest, dishonorable, doubtful, dubious, duplicitous, evasive, FALSE, falsehearted, feline, felonious, finagling, fishy, fraudulent, furtive, guileful, hidlings, hole-and-corner, hugger-mugger, ill-got, ill-gotten, immoral, indirect, insidious, not kosher, privy, questionable, quiet, rotten, scheming, shady, shameless, sharp, shifty, sinister, skulking, slinking, slinky, slippery, sly, sneaking, sneaky, stealthy, surreptitious, suspicious, treacherous, trickish, tricky, two-faced, unconscienced, unconscientious, unconscionable, under-the-counter, under-the-table, undercover, underground, underhand, undermanned, understaffed, unethical, unobtrusive, unprincipled, unsavory, unscrupulous, unstraightforward, wily, without remorse, without shame