hilarious

UK: /hɪˈlɛəriəs/

US: /hɪˈlɛriəs, -ˈlær-/

US: (hi lâr′ē əs, -lar′-, hī-)

WordReference Random House Learner's Dictionary of American English © 2025

hi•lar•i•ous /hɪˈlɛriəs, -ˈlær-/   adj. 

1. extremely funny:
   a hilarious joke.

hi•lar•i•ous•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2025

hi•lar•i•ous  (hi lâr′ē əs, -lar′-, hī-), adj. 

1. arousing great merriment;
   extremely funny:
   a hilarious story; a hilarious old movie.
2. boisterously merry or cheerful:
   a hilarious celebration.
3. merry;
   cheerful.

• Greek hilarós) + -ious
• Latin hilar(is), hilar(us) cheerful (
• 1815–25

hi•lar′i•ous•ly, adv. 
hi•lar′i•ous•ness, n. 
Synonyms

• 2. lively, jolly, rollicking, high-spirited.

Antonyms

• 2. sad, serious, solemn.

Collins Concise English Dictionary © HarperCollins Publishers::

hilarious / hɪˈlɛərɪəs/ adjective

1. very funny or merry

Etymology: 19th Century: from Latin hilaris glad, from Greek hilaros

hiˈlariously adverb

hiˈlariousness noun