Scrap seeing resistance in bar (7)
I believe the answer is:
excerpt
'scrap' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'resistance in bar' is the wordplay.
'resistance' becomes 'r' (abbreviation in physics and electronics).
'in' indicates putting letters inside.
'bar' becomes 'except' (both can mean 'not including').
'r' placed within 'except' is 'EXCERPT'.
'seeing' is the link.
Can you help me to learn more?
(Other definitions for excerpt that I've seen before include "newspaper clipping" , "1D [CLIP]" , "Just a few words" , "Short passage" , "Piece (of music or book)" .)