The meaning of EPHEMERAL is lasting a very short time. How to use ephemeral in a sentence. The Mayfly Helps to Illustrate Ephemeral Synonym Discussion of Ephemeral. ephemeral (comparative more ephemeral, superlative most ephemeral) Lasting for a short period of time. synonyms, antonyms quotations Synonyms: temporary, transitory, fleeting, evanescent, momentary, short-lived, short, volatile; see also Thesaurus: ephemeral Antonyms: permanent, eternal, everlasting, timeless 1821-1822, Vicesimus Knox, Remarks on the tendency of certain Clauses in a Bill now pending in Parliament to degrade Grammar Schools Esteem, lasting esteem, the esteem of good men, like ... The word of the day is ephemeral. Develop your vocabulary by learning the meaning, origin, usage, synonyms, and antonyms of the word ephemeral here. EPHEMERAL meaning: 1. lasting for only a short time: 2. lasting for only a short time: 3. lasting for only a short…. Learn more.