CSS Solved Synonyms and Antonyms

Eternity (Noun) means: Time without limit especially life continuing without end after death.
Whereas, “Transience” (Noun) means: Continuing for a short time; fleeting; temporariness. Here, the correct answer is “Transience”.
Synonyms
Synonyms of ‘Eternity’ are:
Permanence, aeon, afterlife, age, ages, endlessness, everlastingness, immortality, infiniteness, timelessness, infinity, infinitude, etc.
Antonyms
Antonyms of ‘Eternity’ are:
Transience, instability, volatility, caducity, mutability, shortness, impermanence, transient, short-lived, mortal, etc.