Definition of "hilarity"

In the rattle of the box, and of their agreeable conversation, Sir Francis’s spirits rose to their accustomed point of feeble hilarity.

1848 November – 1850 December, William Makepeace Thackeray, chapter 46, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

Think it not curious if we don't seem to be as sidesplittingly impressed with the hilarities in this picture as its promotion might lead you to expect. Hilarity is in it—hilarity at its best—as would be almost mandatory in any film with Miss Holliday.

1999, Vincent Canby, Janet Maslin, Peter M. Nichols, The New York times guide to the best 1000 movies ever made

Many other Latin imports have become staples of our diet, like the burrito, which in Spanish means "little donkey." What other food-related hilarities are we missing out on?

2005, Library journal, volume 130, numbers 8-13, page 122