Added 10 October 2026 one-of-a-kind adjective adjective ! Definition from Wiktionary (CC BY-SA). More about one-of-a-kind at Wordnik → Where our words come from → Unique, singular, sui generis. noun A unique example. Related Words: uniqueone-offone-timesoleexceptionalsingleoutstandingfirst-of-its-kindaloneununiqueunreplicatable Back to today's word