Field is home next to harbour (7)
I believe the answer is:
paddock
'field' is the definition.
(I've seen this before)
'home next to harbour' is the wordplay.
'home' becomes 'pad' (pad can mean a person's home).
'next to' says to put letters next to each other.
'harbour' becomes 'dock' (I've seen this before).
'pad'+'dock'='PADDOCK'
'is' is the link.
(Other definitions for paddock that I've seen before include "Horse-training field" , "enclosed field" , "Small field for horses" , "Pen for racehorses" , "Where horses are paraded before a race" .)