Large female wearing short coat, one exposed seam that’s cut (8)
I believe the answer is:
coalface
'large female wearing short coat one exposed' is the definition.
I can't judge whether this definition defines the answer.
'seam that's cut' is the wordplay.
'seam' becomes 'coal seam' (coal seam is a kind of seam).
'that's cut' becomes 'face' (I can't explain this - if you can you should believe this answer much more).
'coal'+'face'='COALFACE'
Can you help me to learn more?
(Other definitions for coalface that I've seen before include "At which miner works" , "Part of mine" , "Where the action is - in a mine?" , "Where the real work takes place!" .)