At home, dates are used as a substitute (7)
I believe the answer is:
instead
'as a substitute' is the definition.
(I've seen this before)
'at home dates are used' is the wordplay.
'at' is a charade indicator (letters next to each other).
'home' becomes 'in' ('he's home' can mean 'he's in'**).
'are used' is an anagram indicator.
'dates' is an anagram of 'stead'.
'in' put next to 'stead' is 'INSTEAD'.
(Other definitions for instead that I've seen before include "In place (of)" , "for a change" , "Alternatively" , "as an alternative option" , "In lieu" .)