Competition level terrific at first (5)
I believe the answer is:
event
'competition' is the definition.
(I've seen this before)
'level terrific at first' is the wordplay.
'level' becomes 'even' ('even' can be a synonym of 'level'**).
'at first' indicates taking the first letters.
The first letter of 'terrific' is 't'.
'even'+'t'='EVENT'
(Other definitions for event that I've seen before include "special occasion" , "Thing that happens" , "Anything which happens" , "Occurence, occasion" , "major incident" .)