A quick game with mates? (5,5)
I believe the answer is:
speed chess
'mates?' is the definition.
Both the definition and answer are singular nouns.
I also know that 'mates' relates to this answer.
'a quick game' is the wordplay.
'a quick' becomes 'speed' (I can't explain this - if you can you should give a lot more credence to this answer).
'game' becomes 'chess' (chess game is a kind of game).
'speed'+'chess'='SPEED CHESS'
'with' acts as a link.
(Other definitions for speed chess that I've seen before include "movement of men with expedition" , "which leaves little time for mate" , "attempt to mate quickly" .)