Major component of body paint, as you can hear (4)
I believe the answer is:
limb
'major component of body' is the definition.
The definition and answer can be both body parts as well as being singular nouns.
Maybe there's a link between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for limb that I've seen before include "A supporter" , "Substantial branch from a tree trunk" , "Branch - member" , "as part of plane, say" , "Large tree branch" .)