'Hilarious' definitions:

Definition of 'hilarious'

From: WordNet
adjective
Marked by or causing boisterous merriment or convulsive laughter; "hilarious broad comedy"; "a screaming farce"; "uproarious stories" [syn: hilarious, screaming(a), uproarious]

Definition of 'Hilarious'

From: GCIDE
  • Hilarious \Hi*la"ri*ous\, a. [L. hilaris, hilarus, Gr. ?; cf. ? gracious, kindly.] Mirthful; noisy; merry. [1913 Webster]