In need of repair, once, a boat (5)
I believe the answer is:
canoe
'boat' is the definition.
(canoe is a kind of boat)
'in need of repair once a' is the wordplay.
'in need of repair' indicates an anagram.
'once'+'a'='oncea'
'oncea' is an anagram of 'CANOE'.
(Other definitions for canoe that I've seen before include "Light boat propelled with paddle" , "Primitive boat" , "Hunting vessel originating in Haiti" , "River craft" , "Light, narrow open boat" .)