Synonyms of underhand

1 Syllable

shark, shrewd, slyer, sly, slier, sliest, qt, slyest, wily

2 Syllables

sneaking, sneakier, shiftier, crooked, secret, unfair, shrewdest, scheming, sneakiest, roguish, stealthy, snaking, tricky, cunning, unjust, devious, stealthiest, shrewder, shiftiest, hush-hush, shifty, shady, covert, sneaky, crafty, stealthier

3 Syllables

concealed, deceitful, sub-rosa, sidelong, treacherous, dishonest, two-faced, two-timing, guileful, longwinded, indirect, insidious, slippery, oblique, argute, fraudulent, furtive

4 Syllables

secretive, underhanded, unscrupulous, unreliable, hole-and-corner, unprincipled, duplicitous, deceptive, undercover, dirty-dealing, unethical, clandestine, double-crossing, unconscientious, surreptitious

5 Syllables

dishonorable, exploitative

6 Syllables

prevaricatory, circumlocutory