Joker moving rents up (7)
I believe the answer is:
punster
'joker' is the definition.
(someone who makes puns)
'moving rents up' is the wordplay.
'moving' indicates anagramming the letters (letters are moved around).
'rents'+'up'='rentsup'
'rentsup' anagrammed gives 'PUNSTER'.
(Other definitions for punster that I've seen before include "One makes jokes" , "Verbal joker" , "Comedian" , "One who plays on words" , "user of wordplay" .)