Right in leaving out passage (7)
I believe the answer is:
excerpt
'passage' is the definition.
(I know that excerpt is a type of passage)
'right in leaving out' is the wordplay.
'right' becomes 'r' (abbreviation).
'in' indicates putting letters inside.
'leaving out' becomes 'except' (I've seen this before).
'r' inserted into 'except' is 'EXCERPT'.
(Other definitions for excerpt that I've seen before include "A selection or passage from" , "Passage cut" , "Extract from book or film" , "Literary section" , "Quote" .)