Joke books about getting to 100 (3-2)
I believe the answer is:
ton-up
'100' is the definition.
Both the answer and definition are singular nouns.
Maybe there's an association between them I don't understand?
'joke books about' is the wordplay.
'joke' becomes 'pun' (pun is a type of joke).
'books' becomes 'OT' (abbreviation for Old Testament).
'about' shows that the letters should be reversed in order.
'pun'+'ot'='punot'
'punot' backwards is 'TON-UP'.
'getting to' acts as a link.
Can you help me to learn more?
(Other definitions for ton-up that I've seen before include "going quickly" , "Going at 100 mph" , "At one-hundred mph" , "Going at over 100mph" , "Travelling at one hundred mph" .)