Often a smashing shot (8)
I believe the answer is:
forehand
'shot' is the definition.
(I know that forehand is a type of return)
'often a smashing' is the wordplay.
I cannot really see how this works, but
'a' could be 'an' and 'an' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for forehand that I've seen before include "shot" , "Court action" , "Style of tennis stroke" .)