Time ultimately granted uniform allowance (8)
I believe the answer is:
duration
'time' is the definition.
(duration is a kind of time)
'ultimately granted uniform allowance' is the wordplay.
'ultimately' says to take the final letters.
'uniform' becomes 'u' (phonetic alphabet: alpha, bravo, charlie etc.).
'allowance' becomes 'ration' (I've seen this before).
The last letter of 'granted' is 'd'.
'd'+'u'+'ration'='DURATION'
(Other definitions for duration that I've seen before include "Time scale" , "Term, span, time" , "Around it (anag.)" , "Period during which something continues" , "Length of time" .)