A pronounced bore, but providing a round in the bar (4)
I believe the answer is:
boar
'a pronounced bore but' is the definition.
I can't tell whether this defines the answer.
'a round in the bar' is the wordplay.
'a round' becomes 'o' (o is a circular letter).
'in' is an insertion indicator.
'o' going within 'bar' is 'BOAR'.
'providing' acts as a link.
Can you help me to learn more?
(Other definitions for boar that I've seen before include "Male swine" , "Wild animal, sounds like drill" , "Sow's mate" , "Wild swine" , "A male pig, sounds tedious" .)