On the fourth of July, he could have partnered Cleopatra (5)
I believe the answer is:
anton
'july he could have partnered cleopatra' is the definition.
The definition suggests a singular noun which matches the answer.
'on the fourth' is the wordplay.
'on' means one lot of letters goes inside another (as in clothing 'on' a person).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'fourth' becomes 'anon' (I can't justify this - if you can you should believe this answer much more).
't' put inside 'anon' is 'ANTON'.
'of' is the link.
Can you help me to learn more?
(Other definitions for anton that I've seen before include "..... Chekov" , "Boy" , "-- Bruckner, composer" , "-- Chekhov, Russian dramatist" , "Chekhov, say" .)