Meaning A name which has many variant spellings, meaning 'decendent of Cathasaigh. Decendant of the vigilant one'. Origin of Kacy Celtic , Irish Popular Middle Names Grace, Juliana, Paige Pronunciation 🔊 Listen Kacy KEYSiy Similar Names Keri Lilibeth Eriifeoluwa Kadi Orfalinda Torhild Milani K.C. Leigh Aurene Year by Year Popularity of Kacy