heinous

UK: /ˈheɪnəs/, /ˈhiːnəs/ US: /ˈheɪnəs/ ,(hā′nəs)

WordReference Random House Learner's Dictionary of American English © 2026

hei•nous /ˈheɪnəs/   adj. 

1. very evil and hateful:
   Genocide is a heinous offense.

hei•nous•ly, adv. 
hei•nous•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2026

hei•nous  (hā′nəs), adj. 

1. hateful;
   odious;
   abominable;
   totally reprehensible:
   a heinous offense.

• Gmc) + -eus -ous
• Middle French haineus, equivalent. to haine hatred (derivative of haïr to hate
• Middle English heynous 1325–75

hei′nous•ly, adv. 
hei′nous•ness, n. 
Synonyms

wicked, infamous, flagrant, flagitious, atrocious, villainous, nefarious.

Antonyms

admirable.

Collins Concise English Dictionary © HarperCollins Publishers::

heinous / ˈheɪnəs ˈhiː-/ adjective

1. evil; atrocious

Etymology: 14th Century: from Old French haineus, from haine hatred, from hair to hate, of Germanic origin; see hate

ˈheinously adverb

ˈheinousness noun