Withdraw from contest with slight injury (7)
I believe the answer is:
scratch
'slight injury' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for scratch that I've seen before include "Mark with something sharp" , "Slight wound; score" , "Score - postpone indefinitely" , "Score with a sharp point" , "not much of a handicap" .)