hilarious

Etymology

From Latin hilaris (“cheerful”), from Ancient Greek ἱλαρός (hilarós, “cheerful, merry”), from ἵλαος (hílaos, “propitious, gracious, kind”).

adj

1. Very funny; causing great merriment and laughter.
   a hilarious joke
2. Full of hilarity; merry.
   Rounding up the animals in the misty paddocks, with the blackbirds singing as the morning whitened, he felt hilarious, light-headed. He'd clap the cows on their rumps and shout "Come along, there! Come along there, me Irish darlint." 1944, Douglas Stewart, A Girl with Red Hair, and Other Stories, page 60
   Cold Doctor Pell here refused a very considerable fee. He could on occasion behave handsomely; but I can't learn that blustering, hilarious Doctor Rogerson ever refused his. 1863, Sheridan Le Fanu, The House by the Churchyard