impermanentEnglishOxford American Thesaurusimpermanent adjective life has value precisely because it is impermanent: temporary, nonpermanent, not permanent, transient, transitory, passing, fleeting, momentary, ephemeral, fugitive, fading; short-lived, short-term, short, brief, here today and gone tomorrow; literary evanescent, fugacious. ▷antonyms permanent.