Salesman feels bitter about exhibits (10)
I believe the answer is:
represents
'exhibits' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their -s form.
Perhaps you can see a link between them that I can't see?
'salesman feels bitter' is the wordplay.
'salesman' becomes 'rep' (sales representative).
'feels bitter' becomes 'resents' (to feel resentful is to feel bitter).
'rep'+'resents'='REPRESENTS'
'about' is the link.
Can you help me to learn more?
(Other definitions for represents that I've seen before include "shows" , "plays" , "Stands for" , "Portrays" .)