Chest covering for a chest, possibly (male not female) (9)
I believe the answer is:
stomacher
'chest covering' is the definition.
'stomacher' can be an answer for 'covering' (stomacher is a kind of covering). I'm not certain of the 'chest' bit.
'chest possibly male not female' is the wordplay.
I cannot really see how this works, but
'male' could be 'tom' (I've seen this in other clues) and 'tom' is found in the answer.
'female' could be 'her' (I've seen this before) and 'her' is located in the answer.
The remaining letters 'sac' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'for a' is the link.
Can you help me to learn more?
(Other definitions for stomacher that I've seen before include "Decorative panel on front of gown or bodice" , "clothing" , "ornament worn under bodice" .)