Meaning

noun an ornament at the top of a spire or gable; usually a foliated fleur-de-lis

originFrom Late Middle English finial (“(adjective) final; (noun) ornament at the upper extremity of a pinnacle, spire, etc.”) [and other forms], a variant of final (“pertaining to the close or end of something, last, final”), from Old French final (“last, final; definitive”) (modern French final), from Latin fīnālis (“of or pertaining to the end of something, final; of or pertaining to boundaries”),…

Etymology from Wiktionary, CC BY-SA 3.0