superphenomenal UK /suːpəɹˌfəˈnɒmɪnənəl/US /suːpəɹˌfəˈnɑməˌnɑnəl/ adjective1 •(rare) Superlatively phenomenal or quite remarkable.It is evident that both of these theories regard mind as being a distinct entity of a superphenomenal if not supernatural sort. — 1913 formsmore superphenomenal · most superphenomenal