Books bishop to visit area with dreadful slum (6)
I believe the answer is:
albums
'books' is the definition.
(album is a kind of book)
'bishop to visit area with dreadful slum' is the wordplay.
'bishop' becomes 'b' (abbreviation used in chess).
'to visit' means one lot of letters goes inside another.
'area' becomes 'a' (maths abbreviation).
'with' says to put letters next to each other.
'dreadful' is an anagram indicator.
'slum' is an anagram of '[slum]'.
'a'+'[slum]'='a[slum]'
'b' going inside 'alums' is 'ALBUMS'.
(Other definitions for albums that I've seen before include "Books of photos or music disks" , "Stamp collector's books" , "Photograph books" , "LPs, CDs" , "Music records or photo books" .)