Retired at fun run — lead didn't cut the odds (6,2)
I believe the answer is:
turned in
'retired' is the definition.
('turn in' can be a synonym of 'retire')
'at fun run lead didn't cut the odds' is the wordplay.
'cut the odds' indicates alternate letters (letters in the odd-numbered positions are removed).
'at'+'fun'+'run'+'lead'+'didnt'='atfunrunleaddidnt'
The alternating letters of 'atfunrunleaddidnt' are 'TURNED IN'.
(Other definitions for turned in that I've seen before include "Gave up - went to bed" , "Stopped working - retired" .)