Old man died in flat (3)
I believe the answer is:
pad
'flat' is the definition.
(a person's home)
'old man died' is the wordplay.
'old man' becomes 'pa' (both can mean father).
'died' becomes 'd' (abbreviation next to the year of someone's death).
'pa'+'d'='PAD'
'in' acts as a link.
(Other definitions for pad that I've seen before include "Fill with extra material in order to lengthen" , "Batsman's protection" , "Sports guard; home (colloq.)" , "Guard against impact" , "Absorbent material" .)