ephemeral Syllabification: (e·phem·er·al)Pronunciation: /əˈfem(ə)rəl/Translate ephemeral | into German | into Italian Definition of ephemeral adjective lasting for a very short time:fashions are ephemeral (chiefly of plants) having a very short life cycle. noun an ephemeral plant. Derivatives ephemeralityPronunciation: /əˌfeməˈralitē/ noun ephemerally adverb ephemeralness noun Origin: late 16th century: from Greek ephēmeros (see ephemera) + -alephemeral in other Oxford dictionaries Definition of ephemeral in the British & World English dictionary