Sketch depicting a bit of a blatherskite? (4)
I believe the answer is:
skit
'sketch' is the definition.
(short comedy performance)
'a bit of a blatherskite?' is the wordplay.
'a bit of' indicates the answer is hidden within the clue.
'SKIT' is hidden within 'blatherskite'.
'depicting' is the link.
(Other definitions for skit that I've seen before include "Funny scene" , "Comedy item" , "Short play which makes fun of something" , "'Short comedy sketch, a parody (4)'" , "Burlesque - parody" .)