Tree trunk found in vessel, reportedly (4)
I believe the answer is:
bole
'tree trunk' is the definition.
(I've seen this before)
'vessel reportedly' is the wordplay.
'vessel' becomes 'bowl' (bowl is a kind of vessel).
'reportedly' indicates a 'sounds like' (homophone) clue.
'bowl' is a homophone of 'BOLE'.
'found in' acts as a link.
(Other definitions for bole that I've seen before include "Tree-trunk" , "Tree trunk" .)