However the vessel is returned (3)
I believe the answer is:
but
'however' is the definition.
(I've seen this before)
'the vessel is returned' is the wordplay.
'the vessel' becomes 'tub' (tub is a kind of vessel).
'is returned' is a reversal indicator.
'tub' reversed gives 'BUT'.
(Other definitions for but that I've seen before include "On the contrary" , "Conjunction meaningn on the other hand" , "Only in attribution" , "However" , "Except; nevertheless" .)