Try on extremely tasteless suit (6)
I believe the answer is:
hearts
'suit' is the definition.
(I've seen this before)
'try on extremely tasteless' is the wordplay.
'try' becomes 'hear' (as in to try someone in court or hear their case**).
'on' means one lot of letters go next to another.
'extremely' says to hollow out the word (remove centre letters).
'tasteless' with its centre taken out is 'ts'.
'hear'+'ts'='HEARTS'
(Other definitions for hearts that I've seen before include "quarterdeck?" , "Playing-card suit" , "Suit for vital organs" , "Central parts" , "Scots club nickname; suit" .)