Strong's 4190 (πονηρός)

bad, evil, grievous, harm, lewd, malicious, wicked(-ness)

hurtful, i.e. evil (properly, in effect or influence, and thus differing from G2556 (κακός), which refers rather to essential character, as well as from G4550 (σαπρός), which indicates degeneracy from original virtue); figuratively, calamitous; also (passively) ill, i.e. diseased; but especially (morally) culpable, i.e. derelict, vicious, facinorous; neuter (singular) mischief, malice, or (plural) guilt; masculine (singular) the devil, or (plural) sinners

from a derivative of G4192 (πόνος);