Origin of fastidious
Word Origin for fastidious
mid-15c., "full of pride," from Latin fastidiosus "disdainful, squeamish, exacting," from fastidium "loathing, squeamishness," most likely from *fastu-taidiom, a compound of fastus "contempt, arrogance" and taedium "aversion, disgust." Early use in English was both in passive and active senses. Meaning "squeamish, over-nice" emerged in English 1610s. Related: Fastidiously; fastidiousness.