Englishknavish
adjective
archaic
his knavish behaviour:
dishonourable, unprincipled, unscrupulous, ignoble, untrustworthy, roguish, rascally, scoundrelly, mischievous, reprobate, unregenerate, villainous, wicked, depraved, bad, immoral, fiendish, devilish;
dishonest, deceitful, fraudulent, corrupt, lying, deceptive;
base, contemptible, despicable, discreditable, shabby;
informal shady, crooked;
archaic scurvy, dastardly.
▷antonyms honourable, noble, virtuous.
knavish Oxford Dictionary of English