Changes into suits (7)
I believe the answer is:
becomes
I believe this clue is a double definition.
'changes into' is the first definition.
(I've seen this before)
'suits' is the second definition.
('become' can be a synonym of 'suit')
(Other definitions for becomes that I've seen before include "Suits, befits" , "Turns into" , "Changes into" , "Gets" , "Undergoes a change" .)