Some prequalify in uniform (5)
I believe the answer is:
equal
'uniform' is the definition.
(I've seen this before)
'some prequalify in' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'EQUAL' is hidden in the letters of 'prequalify in'.
(Other definitions for equal that I've seen before include "Like revolting farm animals" , "Peer; rival" , "Be as good as, match" , "What = means" , "Alike" .)