Briefly train for a fight in Bath? (3)
I believe the answer is:
spa
'bath?' is the definition.
(Bath is a spa town)
'briefly train for a fight' is the wordplay.
'briefly' means to remove the last letter.
'train for a fight' becomes 'spar' (I've seen this in another clue).
'spar' with its last letter taken off is 'SPA'.
'in' acts as a link.
(Other definitions for spa that I've seen before include "Watering-place" , "Bath, possibly" , "Health resort at a mineral spring" , "Healthy place" , "Cheltenham or Bath?" .)