Stop big name in NYC sport making a comeback (4)
I believe the answer is:
stem
'stop' is the definition.
(stem can mean to stop or interrupt)
'big name in nyc sport making a comeback' is the wordplay.
I cannot quite see how this works, but
'name' could be 'em' and 'em' is found in the answer.
The remaining letters 'st' 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).
Can you help me to learn more?
(Other definitions for stem that I've seen before include "Slender vertical part, glass or plant" , "Upward part of a plant" , "Stop; stalk; ship's timber" , "Restrain the flow of" , "Dam" .)