Aid when strolling round love boat (5)
I believe the answer is:
canoe
'boat' is the definition.
(canoe is a kind of boat)
'aid when strolling round love' is the wordplay.
'aid' becomes 'cane' (walking aid).
'when strolling round' means one lot of letters goes inside another.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'cane' placed around 'o' is 'CANOE'.
(Other definitions for canoe that I've seen before include "Light, narrow open boat" , "Boat one paddles" , "Boat that's paddled" , "Ocean (anag)" , "Light boat propelled with paddle" .)