Become obsolescent in time (4)
I believe the answer is:
date
'time' is the definition.
(I know that time can be written as date)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for date that I've seen before include "escort" , "Rendezvous" , "Tropical fruit" , "may be fruitful" , "Sticky fruit" .)