Etymology tree Latin liber Ancient Greek -ο- (-o-)der. Latin -o-bor. English -o- English libro- Proto-Italic *kubāō Latin cubō Latin -i- Proto-Indo-European *-tḗr Proto-Indo-European *-trom Proto-Indo-European *-tlom Proto-Italic *-klom Latin -culum Latin cubiculum Proto-Indo-European *h₂el- Proto-Indo-European *-is Proto-Indo-European *h₂élisder.? Proto-Italic *-ālis Latin -ālis Latin -āris Latin cubiculārislbor. English cubicular Proto-Indo-European *-id- Proto-Indo-European *-yéti Proto-Indo-European *-idyéti Proto-Hellenic *-íďďō Ancient Greek -ῐ́ζω (-ĭ́zō) Proto-Hellenic *-tās Ancient Greek -τής (-tḗs) Ancient Greek -ῐστής (-ĭstḗs)bor. Latin -istader. Old French -istebor. Middle English -ist English -ist English librocubicularist Coined by the American writer Christopher Morley (1890–1957) in The Haunted Bookshop (1919; see the quotation), probably from libro- (prefix meaning ‘book’) + cubicular (“(obsolete) belonging to a bedchamber”) + -ist (suffix denoting one who engages in a particular type of activity). Cubicular is a learned borrowing from Latin cubiculāris (“relating to a bedroom”), from cubiculum (“small bedroom, bedchamber”) + -āris (“suffix meaning ‘of or pertaining’ to forming adjectives”); and cubiculum is derived from cubāre (the present active infinitive of cubō (“to lie down, recline; to sleep”), possibly ultimately from Proto-Indo-European *ḱewb-) + -i- (interfix used between stems and suffixes) + -culum (an inflected form of -culus, a variant of -ulus (diminutive suffix)).