Have some tomorrow night (3)
I believe the answer is:
own
'have' is the definition.
(synonyms)
'some tomorrow night' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'OWN' is hidden within 'tomorrow night'.
(Other definitions for own that I've seen before include "Be in legal possession of (3)" , "Acknowledge" , "Control" , "Keep" , "Private" .)