Have some tomorrow Nicholas (3)
I believe the answer is:
own
'have' is the definition.
(to have something is to own it)
'some tomorrow nicholas' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'OWN' can be found hidden inside 'tomorrow nicholas'.
(Other definitions for own that I've seen before include "Have in one's possession" , "Allow" , "Possess - recognise - admit" , "Acknowledge" , "Keep" .)