Will takes canoe at last into Wash (5)
I believe the answer is:
leave
'will' is the definition.
('leave' can be a synonym of 'will')
'canoe at last into wash' is the wordplay.
'at last' suggests the final letters.
'into' indicates putting letters inside.
'wash' becomes 'lave' ('lave' can be a synonym of 'wash').
The final letter of 'canoe' is 'e'.
'e' put within 'lave' is 'LEAVE'.
'takes' is the link.
(Other definitions for leave that I've seen before include "taken by those on the way out" , "Go away on holiday" , "Furlough" , "Green light" , "Go - on holidays?" .)