1) Acting 2) Changeable 3) Ephemeral 4) Erasable 5) Evanescent 6) Finite 7) Fly-by-night 8) Fugacious 9) Guest 10) Improvised 11) Interim 12) Makeshift 13) Passing 14) Provisional 15) Temporal 16) Temporary 17) Terminable 18) Transient 19) Transitory 20) Unstable 21) Visiting 1) Acting 2) Ephemeral 3) Episodic 4) Evanescent 5) French word used in English 6) Fugacious 7) Guest 8) Improvised 9) Interim 10) Jury-rigged 11) Makeshift 12) Not lasting 13) Not permanent 14) Not permanent or enduring 15) Passing 16) Pro tem 17) Pro tempore 18) Short-lived 19) Temporal 20) Temporary 
• (a.) Not permanent.
Im·per'ma·nent adjective Not permanent. 
[adj] - not permanent 2. [adj] - existing or enduring for a limited time only
temporary adjective not permanent; not lasting; `politics is an impermanent factor of life`- James Thurber; `impermanent palm cottages`; `a temperary arrangement`; `temporary housing`
not permanent or enduring; transitory.