Vessel in plot set on fire (6)
I believe the answer is:
burned
'set on fire' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'vessel in plot' is the wordplay.
'vessel' becomes 'urn' (urn is a type of container).
'in' means one lot of letters goes inside another.
'plot' becomes 'bed' (a plot of land).
'urn' placed inside 'bed' is 'BURNED'.
Can you help me to learn more?
(Other definitions for burned that I've seen before include "Set fire to" , "Blazed" .)