For every expert has it (3)
I believe the answer is:
per
'for every' is the definition.
('per' means 'for each' or 'for every')
'expert has it' is the wordplay.
'has it' says the answer is hidden in the clue.
'PER' is hidden in the letters of 'expert'.
(Other definitions for per that I've seen before include "Preposition meaning for each" , "For each or every" , "According to" , "Preposition indicating by means of" .)