Which word is a synonym for the ephemeral?

Here are some synonyms for "ephemeral," depending on the specific nuance you want to convey:

General synonyms:

* Transient

* Fleeting

* Short-lived

* Momentary

* Passing

* Temporary

More literary synonyms:

* Fugacious

* Evanescent

* Mercurial

Synonyms emphasizing impermanence:

* Transitory

* Impermanent

* Short-lasting

The best synonym for "ephemeral" will depend on the specific context and what you want to emphasize.