Associate equal to rent review (7)
I believe the answer is:
partner
'associate' is the definition.
(I know that partner is a type of associate)
'equal to rent review' is the wordplay.
'equal' becomes 'par'.
'to' says to put letters next to each other.
'review' is a reversal indicator.
'rent' reversed gives 'tner'.
'par'+'tner'='PARTNER'
(Other definitions for partner that I've seen before include "Mate or collaborator" , "sometimes joining in crime" , "Significant other" , "Other half?" , "Either member of a couple" .)