Warning not to leave (3,4)
I believe the answer is:
you wait
'warning' is the definition.
('just you wait!')
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for you wait that I've seen before include "Words of warning" , "When service is slow" , "Threat" , "take your turn" , "there will be trouble" .)