unkindly (adv.)

c. 1200, "unsuitably, improperly," from un- (1) "not" + kindly (adv.). From mid-15c. as "discourteously, maliciously."

early 13c., "not natural, unnatural," from un- (1) "not" + kindly (adj.). From c. 1300 as "without natural affection, unfraternally." Old English had ungecyndelic.