A rum ace, funny clown (7)
I believe the answer is:
marceau
'clown' is the definition.
(I know that Marceau has the occupation clown)
'a rum ace funny' is the wordplay.
'funny' indicates anagramming the letters.
'a'+'rum'+'ace'='arumace'
'arumace' is an anagram of 'MARCEAU'.
(Other definitions for marceau that I've seen before include "Marcel -, French mime artist" , "famous artist speechless" , "Famous French mime artist" .)