Three card players in silly female attire (7)
I believe the answer is:
twinset
'female attire' is the definition.
'twinset' can be an answer for 'attire' (type of clothing). I'm unsure of the 'female' bit.
'three card players in silly' is the wordplay.
'three card players' can mean three substitutions for 'card player'.
'card player' becomes 'n' (bridge players are known by compass position).
'card player' becomes 's' (bridge players are known by compass position).
'card player' becomes 'e' (bridge players are known by compass position).
'in' is an insertion indicator.
'silly' becomes 'twit' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'n'+'s'+'e'='nse'
'nse' placed into 'twit' is 'TWINSET'.
Can you help me to learn more?
(Other definitions for twinset that I've seen before include "Kit worn to match" , "Wear associated with pearls?" , "Matching garments" , "clothing" , "coordinated clothes" .)