Scrap about a joint (6)
I believe the answer is:
shared
'joint' is the definition.
(eg in joint ownership)
'scrap about a' is the wordplay.
'scrap' becomes 'shred' (both can mean a small amount of material).
'about' indicates putting letters inside.
'shred' going around 'a' is 'SHARED'.
(Other definitions for shared that I've seen before include "Jointly owned" , "Participated in" , "Possessed in common" , "Jointly possessed" , "divided into portions" .)