Attribute wrinkled up with time (6)
I believe the answer is:
impute
'attribute' is the definition.
(synonyms)
'wrinkled up with time' is the wordplay.
'wrinkled' indicates an anagram (I've seen this in other clues).
'with' is a charade indicator (letters next to each other).
'up' put after 'time' is 'timeup'.
'timeup' with letters rearranged gives 'IMPUTE'.
(Other definitions for impute that I've seen before include "Uptime (anag.)" , "'Attribute, assign (6)'" , "Attribute or ascribe - say fault" , "take into account" , "Attribute (something bad) to someone" .)