Does try to enter the competitions (8)
I believe the answer is:
contests
'the competitions' is the definition.
('contest' can be a synonym of 'competition')
'does try to enter' is the wordplay.
'does' becomes 'cons' (both can mean to commit fraud).
'try' becomes 'test' (test is a kind of try).
'to enter' is an insertion indicator.
'cons' going around 'test' is 'CONTESTS'.
(Other definitions for contests that I've seen before include "sporting events?" , "Struggles between rivals" , "Competitions, struggles" , "Competitions between rivals" , "Matches" .)