the word "truffle" entered english in the late 16th century from the french "truffle," itself a derivative of the older "truffe." the french term likely originates from the vulgar latin "tufera," a variation of the latin "tuber," meaning "lump" or "swelling," which was used to describe the edible fungus. the latin "tuber" itself is derived from the pie root "teue-," meaning "to swell." the semantic journey is direct, from a general term for a swollen lump to the specific, highly-prized subterranean fungus. the later application to a round chocolate confection in the 20th century is a metaphorical extension based on the visual resemblance to the lumpy fungus.

this word is a simplex loanword. it does not contain separable morphemes within its modern english spelling.