Crossword Genius

Suit to change into (6)

Ross

I believe the answer is:

become

Here is my best explanation:

I believe this clue is a double definition.

'suit' is the first definition.
('become' can be a synonym of 'suit')

'change into' is the second definition.
(thesaurus)

'to' acts as a link.

This clue was last seen in Evening Standard