Scrap of courage (3)
I believe the answer is:
rag
'scrap' is the definition.
(I've seen this before)
'of courage' is the wordplay.
'of' says the answer is hidden in the clue.
'RAG' is hidden in the letters of 'courage'.
(Other definitions for rag that I've seen before include "Syncopated piano music" , "charity event" , "Disreputable newspaper" , "Torn piece of cloth or university japes" , "Disreputable paper" .)