heinous (adj.)

late 14c., "hateful, odious, atrocious," from Old French hainos "inconvenient, awkward; hateful, unpleasant; odious" (12c., Modern French haineux), from haine "hatred, hate," from hair "to hate," from Frankish, from Proto-Germanic *hatjan, from PIE *kad- "sorrow, hatred" (see hate (v.)). Related: Heinously; heinousness.