Bulges of cobblers covered up by puritans (9)
I believe the answer is:
'bulges' is the definition.
('protrude' can be a synonym of 'bulge')
'cobblers covered up by puritans' is the wordplay.
'cobblers' becomes 'rot' (I've seen this before).
'covered up by' is an insertion indicator.
'puritans' becomes 'prudes' ('prude' can be a synonym of 'puritan').
'rot' going within 'prudes' is 'PROTRUDES'.
'of' is the link.
(Another definition for protrudes that I've seen is " Sticks out".)