Synonyms to underhand

amoral, conscienceless, corrupt, corrupted, criminal, crooked, dark, devious, dishonest, dishonorable, doubtful, dubious, evasive, felonious, fishy, fraudulent, ill-got, ill-gotten, immoral, indirect, insidious, nonmoral, not kosher, questionable, rotten, shady, shameless, shifty, sinister, slippery, steeped in vice, suspicious, tricky, unconscienced, unconscientious, unconscionable, underhanded, unethical, unmoral, unprincipled, unsavory, unscrupulous, unstraightforward, vice-laden, vice-prone, vicious, without remorse, without shame, artful, Byzantine, Machiavellian, Machiavellic, acute, adroit, ambidextrous, arch, astute, cagey, calculating, canny, chiseling, clever, collusive, covinous, crafty, cunning, cute, deceitful, deep, deep-laid, designing, dexterous, diplomatic, disingenuous, double, double-dealing, double-faced, double-minded, double-tongued, doublehearted, duplicitous, facile, faithless, false, false-principled, falsehearted, feline, finagling, forsworn, foxy, furtive, guileful, ingenious, insincere, inventive, knowing, oily