Pursue spades, say, in sporting attire (9)
I believe the answer is:
tracksuit
'attire' is the definition.
(I know that tracksuit is a type of sportswear)
'pursue spades say' is the wordplay.
'pursue' becomes 'track' (tracking is a kind of pursuing).
'spades say' becomes 'suit' (spades is an example of a card suit).
'track'+'suit'='TRACKSUIT'
'in sporting' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tracksuit that I've seen before include "Warm loose-fitting garment for exercising" , "it's assumed, if exercising" , "Sportswear" , "Loose-fitting top and bottom for athlete warming up" , "Loose sports/casual wear" .)