(adj.) completely funny
Something that is pantogelastic, we now know from today’s Word of the Day, is completely, hilariously funny.
The ‘panto–’ at the head of that word means ‘all’, which is why a pantoscope is a device for quite literally seeing everything; a pantagamy as a community in which everyone is married to each other; and a pantomime is literally an ‘imitator of everything’, as early pantomime performers were supposed to be.
The ‘–gelastic’ part of that is more obscure, and crops up in only a handful of English words—including the word gelastic itself, an adjective describing anything comedic or intended to be humorous. It derives from gelao, the Greek word for ‘laugh’, from which English has developed this term as well as the likes of agelast, meaning ‘a person who never laughs’, and gelasin, a delightful seventeenth century word for a dimple produced by laughing or smiling.
This word, meanwhile, is a relatively more contemporary coinage: we’ve been finding things pantogelastic only since the early 1900s.