Have some marrow Neddy (3)
I believe the answer is:
own
'have' is the definition.
(to have something is to own it)
'some marrow neddy' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'OWN' is hidden within 'marrow neddy'.
(Other definitions for own that I've seen before include "Acknowledge" , "Possess or confess" , "Control" , "Possess - recognise - admit" , "Keep" .)