Books (5)
'books' is the definition.
(tome is a kind of book)
This is all the clue.
(Other definitions for tomes that I've seen before include "works" , "Large scholarly books" , "Big books" , "Weighty books" .)
'books' is the definition.
('volume' can be a synonym of 'book')
This is the entire clue.
(Other definitions for volumes that I've seen before include "encyclopedia?" , "Parts of periodical publication" , "Books (in a series)" .)