Huge soldier gets a book (5)
I believe the answer is:
giant
'huge' is the definition.
(I know that huge can be written as giant)
'soldier gets a book' is the wordplay.
'soldier' becomes 'GI' (term for US soldier).
'gets' means one lot of letters go next to another.
'book' becomes 'nt' (New Testament).
'gi'+'a'+'nt'='GIANT'
(Other definitions for giant that I've seen before include "Large black and white mammal" , "Creature of exceptional size" , "Huge person" , "Jumbo" , "Huge; James Dean film" .)