Trendy suit, to a large degree (2,6)
I believe the answer is:
in spades
'to a large degree' is the definition.
(I've seen this before)
'trendy suit' is the wordplay.
'trendy' becomes 'in'.
'suit' becomes 'spades' (I've seen this before**).
'in'+'spades'='IN SPADES'
(Other definitions for in spades that I've seen before include "to a high degree" , "Extremely" , "to a great extent" , "how a contract may be agreed" , "Unquestionably - how a bridge hand might be played?" .)