Lasting only a short time (9)
(Other definitions for ephemeral that I've seen before include "just for a day?" , "not going to last long" , "Transitory" , "short term gain" , "Having only brief existence" .)
(Other definitions for temporary that I've seen before include "here today, gone tomorrow" , "Lasting for a limited period" , "not for good" , "For a short period only" , "Not for long" .)
(Other definitions for fleeting that I've seen before include "Ephemeral" , "Momentary" , "Lasting for a brief time" , "Passing quickly, transitory" , "Evanescent" .)