Extravagantly fashionable suit (2,6)
I believe the answer is:
in spades
'extravagantly' is the definition.
I know nothing about this answer so I can't judge whether this works.
'fashionable suit' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'suit' becomes 'spades' (playing card suit).
'in'+'spades'='IN SPADES'
Can you help me to learn more?
(Other definitions for in spades that I've seen before include "Seriously" , "Where a contract may be made" , "Without restraint" , "to a great extent" , "to a large degree" .)