For every part of experience (3)
I believe the answer is:
per
'for every' is the definition.
('per' means 'for each' or 'for every')
'part of experience' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'PER' is hidden within 'experience'.
(Other definitions for per that I've seen before include "According to" , "Preposition indicating by means of" , "For each or every" , "Preposition meaning for each" .)