The short way out of Newhaven (3)
I believe the answer is:
ave
'the short way' is the definition.
(abbreviation for avenue, a type of 'way'; 'short' indicates an abbreviation)
'of newhaven' is the wordplay.
'of' indicates a hidden word.
'AVE' is hidden within 'newhaven'.
'out' acts as a link.
(Other definitions for ave that I've seen before include "Hello to the old Romans" , "Hail to the old Romans" , "Hail (Latin)" , "Cockney's own" , "Hail as to Caesar" .)