1. (adj)ephemeron, ephemeral anything short-lived, as an insect that lives only for a day in its winged form Synonyms: ephemeral, ephemeron Antonyms: lasting, permanent
2. (adj)ephemeral, passing, short-lived, transient, transitory, fugacious lasting a very short time Synonyms: passing, short-lived, passing(a), ephemeral, pass(a), transeunt, cursory, transitory, perfunctory, fugacious, casual, transient Antonyms: lasting, permanent