Exercise for us at closing time (3)
I believe the answer is:
use
'exercise' is the definition.
(synonyms)
'us at closing time' is the wordplay.
'at' means one lot of letters go next to another.
'closing time' becomes 'e' (I can't explain this - if you can you should believe this answer much more).
'us'+'e'='USE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for use that I've seen before include "Operate" , "Exploit; custom" , "Apply, employ" , "Milk" , "Put to work" .)