The Oxford Thesaurus An A-Z Dictionary of Synonyms - groan v.

1) moan, sigh, murmur, wail, whimper, whine: Unattended patients were lying there, groaning in agony. 2) complain, grumble, grouse, object, protest, Colloq gripe, beef, yammer, Brit whinge, Slang bitch: Now that he's rich, he's groaning about taxes. --n. 3) moan, sigh, murmur, wail, whimper, whine: I thought I heard a groan coming from the attic. 4) complaint, grumble, grousing, muttering, Colloq gripe, griping, beef, yammering, Slang bitching: His announcement that the whole class would be punished was met by groans.