Leave out river in passage (7)
I believe the answer is:
excerpt
'passage' is the definition.
(excerpt is a kind of passage)
'leave out river in' is the wordplay.
'leave out' becomes 'except' ('except' can be a synonym of 'leave out').
'river' becomes 'r'.
'in' indicates putting letters inside.
'except' going around 'r' is 'EXCERPT'.
(Other definitions for excerpt that I've seen before include "1D [CLIP]" , "Selection, extract" , "Passage from literature or music" , "Passage selected from a book" , "part of programme" .)