Book gives nothing in two months, in my opinion (10)
I believe the answer is:
octodecimo
'book gives nothing' is the definition.
'octodecimo' can be an answer for 'book' (I've seen this before). I'm not sure about the 'gives nothing' bit.
'two months in my opinion' is the wordplay.
'two months' can mean two replacements for 'month'.
'month' becomes 'octo' (I am not sure about this - if you are sure you should believe this answer much more).
'month' becomes 'dec' (abbreviation for December).
'in my opinion' becomes 'imo' (common abbreviation).
'octo'+'dec'+'imo'='OCTODECIMO'
'in' acts as a link.
Can you help me to learn more?
(Another definition for octodecimo that I've seen is " Book".)