The word fungus was first used in the year 1527 by translator Laurence Andrewe in a book he wrote on distillation of water. Nothing was new about this except the language it was attested in; the word had the same spelling and definition in Latin. In earlier variations, however, fungus more commonly took the form sfungus, and it comes from the Ancient Greek word spongos, meaning "sponge" (which through Latin spongia, is also the etymon of our English word sponge). We don't know where spongos comes from, but there are some observed cognates, like Armenian sunkn ("tree-mushroom") that hint at a possible origin in a Pre-Mediterranean or otherwise non-Indo-European language. Popularity of the word fungus peaked in 1912 and has been declining since then.
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.