Seven different levels (5)
I believe the answer is:
evens
'levels' is the definition.
('even' can be a synonym of 'level')
'seven different' is the wordplay.
'different' indicates an anagram (letters placed in a different order).
'seven' is an anagram of 'EVENS'.
(Other definitions for evens that I've seen before include "Likelihood" , "Kind of bet where odds are one to one" , "50-50 odds" , "Levels - odds" , "less likely than 27 [ODDS-ON]" .)