A permit received by the track and field competitor? (7)
I believe the answer is:
athlete
'track and field competitor?' is the definition.
(I've seen this before)
'a permit received by the' is the wordplay.
'permit' becomes 'let' (synonyms).
'received by' is an insertion indicator.
'let' placed inside 'the' is 'thlete'.
'a'+'thlete'='ATHLETE'
(Other definitions for athlete that I've seen before include "Track/field sportsperson" , "Sport participant" , "Sporting person" , "Olympic participant" , "Person fit for physical sports" .)