Uniform on the Spanish team (6)
I believe the answer is:
eleven
'team' is the definition.
(eleven is a kind of team)
'uniform on the spanish' is the wordplay.
'uniform' becomes 'even' (I've seen this before).
'on' says to put letters next to each other.
'the spanish' becomes 'el'.
'even' after 'el' is 'ELEVEN'.
(Other definitions for eleven that I've seen before include "Not first team (6,6) - See 24" , "Cricket 18" , "1 and 1?" , "Players" , "Number in a cricket team" .)