Quiet, Tolkien character might survive this long, perhaps (5,4)
I believe the answer is:
shelf life
'might survive this long perhaps' is the definition.
The definition suggests a singular noun which matches the answer.
'quiet tolkien character' is the wordplay.
I cannot really understand how this works, but
'quiet' could be 'sh' (both can be said to tell someone to be quiet) and 'sh' is present in the answer.
'character' could be 'l' and 'l' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for shelf life that I've seen before include "time when still fresh" , "Time for which a stored item remains usable, as in shop" , "Storage time of product" , "Period for which item is saleable" , "Period for which a stored item remains usable" .)