Poet excluded in conversation (4)
I believe the answer is:
bard
'poet' is the definition.
(I know that poet can be written as bard)
'excluded in conversation' is the wordplay.
'excluded' becomes 'barred' ('bar' can be a synonym of 'exclude').
'in conversation' shows a homophone (sound like).
'barred' is a homophone of 'BARD'.
(Other definitions for bard that I've seen before include "Gray, perhaps" , "Traditional poet" , "A drab sort of old poet" , "A lyric poet" , "Ancient poet" .)