Talk on the phone of an item of property (7)
I believe the answer is:
chattel
'an item of property' is the definition.
(I've seen this before)
'talk on the phone' is the wordplay.
'talk' becomes 'chat' (chat can mean to talk).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'the phone' becomes 'tel' (short for telephone).
'chat'+'tel'='CHATTEL'
'of' is the link.
(Other definitions for chattel that I've seen before include "Personal possession" , "Item of non-freehold property" , "Item of personal property" , "Personal effect" , "Piece of portable property" .)