The accent of a big-headed rascal? (6)
I believe the answer is:
brogue
'the accent' is the definition.
(brogue can mean a Scottish or Irish accent)
'big-headed rascal?' is the wordplay.
'big-headed' becomes 'b' (this might be a standard abbreviation of which I'm unaware).
'rascal?' becomes 'rogue' (both can mean a scoundrel).
'b'+'rogue'='BROGUE'
'of a' is the link.
Can you help me to learn more?
(Other definitions for brogue that I've seen before include "Footprint could be left by this" , "Worn" , "Decorated shoe; accent" , "Oxford" , "Patterned shoe, accent" .)