Book a sailor brought over (5)
I believe the answer is:
atlas
'book' is the definition.
(atlas is a kind of book)
'a sailor brought over' is the wordplay.
'sailor' becomes 'salt' (salt is a kind of sailor).
'brought over' says the letters should be written in reverse.
'salt' reversed gives 'tlas'.
'a'+'tlas'='ATLAS'
(Other definitions for atlas that I've seen before include "Its architectural name is telamon" , "I carry a huge weight" , "God" , "One hugely burdened" , "Mythological Titan (involved with the world of maps?)" .)