Hoodlum not having name for being a joker (7)
I believe the answer is:
gagster
'a joker' is the definition.
(thesaurus)
'hoodlum not having name for' is the wordplay.
'hoodlum' becomes 'gangster' (I've seen this before).
'not having' suggests deleting specific letters.
'name for' becomes 'n' (I've seen this in other clues).
'gangster' with 'n' taken out is 'GAGSTER'.
'being' is the link.
(Other definitions for gagster that I've seen before include "comic" , "Comedian (one letter short of a criminal)" , "Who'll crack you up" , "who makes jokes?" , "Joker" .)