Hilarity, Hilarious

Have you ever found something or someone to be hilarious? Have you ever been hilarious? The word hilarious evolved from simply meaning ‘cheerful’ in 1823 to being ‘boisterously joyful’ by 1835 (what might have happened in those twelve years?!).
 
Have you ever been so exhilarated that you ended up in a state of cachinnation?! The words exhilaration and cachinnation are often a result of hilarity.
 
The word hilarious comes from hilarity, a word that came to English in the mid-15 century meaning cheerfulness, gaiety, merriment. Hilarious and hilarity come from Latin hilarus (cheerful, merry) and Greek hilaros (cheerful, merry, joyous). The words for being cheerful and joyful do not seem to have changed that much over the centuries. The experiences and feelings of cheer and joy probably have not changed that much either.
 
Interestingly, in its origins the word hilarity has its roots in words related to reconciliation; that is, in the happiness or joy that comes when a struggle or conflict is resolved. Greek hilaros comes from hilaskomai (to propitiate, appease, reconcile) and likely from the Proto-Indo-European (PIE) root selh (to reconcile); PIE selh is also the root of Latin solari (to comfort), later in English as solace.
 
The word exhilaration (the act of enlivening or cheering; the state of being enlivened or cheerful) is from the 1620s. The word comes from Latin exhilarationem (a gladdening) and exhilarare (to gladden, to cheer); from ex (out of, thoroughly) + hilarare (to make cheerful) from hilarus.
 
The word cachinnation (loud laughter), from the 1620s, is from Latin cachinnationem (violent laughter, excessive laughter) and cachinnare (to laugh immoderately or loudly). Its origins are unknown but the experience of such laughter seems common everywhere; for example, Latin cachinnare is related to Sanskrit kakhati (laughs), Greek kakhazein (to laugh loudly), Old High German kachazzen, and English cackle. People everywhere are always cracking up about something.
 
Why is cachinnation not a common word in English given that it represents such a common experience? Because this Latin term never took hold in English, it never replaced the Old English word hleahtor (laughter; jubilation; derision), Old Norse hlatr, Danish latter, and Old High German lahtar, all from Proto-Germanic hlahtraz, all of which had put down deep roots in Britain long before the post-1066 Latin influences arrived in force. Laughter, from the late 14th century, and laugh (the action of laughing, from the 1680s) are the words that stuck in the language.
 
By the way, do you know anyone named Hilary? Hilary is a proper name from Latin Hilarius (cheerful).
 
Reference: Online Etymological Dictionary, https://www.etymonline.com/
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