Won a farm for conversion and boat (3-2-3)
I believe the answer is:
man-of-war
'boat' is the definition.
'won a farm for conversion' is the wordplay.
'for conversion' indicates anagramming the letters (I've seen this in other clues).
'won'+'a'+'farm'='wonafarm'
'wonafarm' is an anagram of 'MAN-OF-WAR'.
'and' acts as a link.
(Other definitions for man-of-war that I've seen before include "A battleship - for a fighter?" , "Old naval ship" , "Armed sailing ship" , "Fighting ship" , "Portuguese --, jellyfish" .)