Unusual timer's value (5)
I believe the answer is:
merit
'value' is the definition.
(I've seen this in another clue)
'unusual timer's' is the wordplay.
'unusual' indicates anagramming the letters.
'timer' anagrammed gives 'MERIT'.
(Other definitions for merit that I've seen before include "Excellence that deserves to be honoured" , "Have a right" , "credit" , "Excellence, desert" , "Excellence, worth" .)