Tall chap gives soldier a book (5)
I believe the answer is:
giant
'tall' is the definition.
(thesaurus)
'soldier a book' is the wordplay.
'soldier' becomes 'gi' (government issue or general issue**).
'book' becomes 'nt' (I've seen this in other clues).
'gi'+'a'+'nt'='GIANT'
'chap gives' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for giant that I've seen before include "Creature described in 14 17" , "Very big person" , "Large mythical figure" , "Extremely large (person)" , "Designating big" .)