Intelligence to find empty toy funny (5)
I believe the answer is:
witty
'funny' is the definition.
(thesaurus)
'intelligence to find empty toy' is the wordplay.
'intelligence' becomes 'wit' (wit is a kind of intelligence).
'to find' is a charade indicator (letters next to each other).
'empty' suggests removing the centre.
'toy' with its middle taken out is 'ty'.
'wit'+'ty'='WITTY'
(Other definitions for witty that I've seen before include "Clever and funny" , "Amusing, droll" , "Sparkling" , "Cleverly amusing" , "Humorous" .)