You bet it's found over in exercise yard (3)
I believe the answer is:
yes
'you bet' is the definition.
(I've seen this in another clue)
'found over in exercise yard' is the wordplay.
'over' is a reversal indicator.
'found' indicates a hidden word.
'sey' is hidden within 'in exercise yard'.
'sey' written backwards gives 'YES'.
'it's' acts as a link.
(Other definitions for yes that I've seen before include "Aye" , "Oui" , "Yea" , "Affirmative reply" , "Affirmative answer" .)