Old English granian "to groan, murmur, lament," from Proto-Germanic *grain- (cognates: Old Norse grenja "to howl"), of imitative origin, or related to grin. Meaning "complain" is from early 13c., especially in Middle English phrase grutchen and gronen. Related: Groaned; groaning.

late 14c., from groan (v); earlier grane (early 14c.).