Bore who talks a great deal (7)
I believe the answer is:
windbag
'bore who talks a great deal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for windbag that I've seen before include "Boring talker" , "Motormouth" , "Bellows" , "one with lots to say" , "One spouting hot air" .)