One beam, say, brought back to son's old property (8)

I believe the answer is:

agedness

'old property' is the definition.

'one beam say brought back to son's' is the wordplay.
'one' becomes 'a'.
'beam' becomes 'send' ('send' can be a synonym of 'beam'**).
'say' becomes 'eg'.
'brought back' shows that the letters should be reversed in order.
'to son's' becomes 's'.
'send'+'eg'='sendeg'
'sendeg' reversed gives 'gednes'.
'a'+'gednes'+'s'='AGEDNESS'

(Another definition for agedness that I've seen is " Antiquity".)

I've seen this clue in The Guardian.

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