Engineer leaving sub gets shot (5)
I believe the answer is:
serve
'shot' is the definition.
(I know that serve is a type of tennis shot)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for serve that I've seen before include "Hand out, food or drink say" , "golfer to sink fourth from fairway" , "Work for; tennis stroke" , "Opening shot at tennis" , "Answer the purpose" .)