Put back some odd books (5)
I believe the answer is:
tomes
'books' is the definition.
(tome is a kind of book)
'put back some odd' is the wordplay.
'back' indicates one should take the final letters (the letter at the back).
'odd' is an anagram indicator.
The last letter of 'put' is 't'.
'some' anagrammed gives 'omes'.
't'+'omes'='TOMES'
(Other definitions for tomes that I've seen before include "works" , "Large scholarly books" , "Big books" , "Weighty books" .)