n. The buttocks; -- a word used with children. [ slang ]
a. [ OF. haïnos hateful, F. haineux, fr. OF. haïne hate, F. haine, fr. haïr to hate; of German origin. See Hate. ] Hateful; hatefully bad; flagrant; odious; atrocious; giving great offense; -- applied to deeds or to character. [ 1913 Webster ]
It were most heinous and accursed sacrilege. Hooker. [ 1913 Webster ]
How heinous had the fact been, how deserving
Contempt! Milton.
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n. the quality of being shockingly cruel and inhumane.