Bird driving another away in scrap (3)
I believe the answer is:
bit
'scrap' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bit that I've seen before include "Segment" , "The boring-piece of a drill" , "Boring tip of a drill" , "something boring" , "Snaffle - small piece" .)