Feed friend initially, then stranger (6)
I believe the answer is:
fodder
'feed' is the definition.
(fodder is a kind of feed)
'friend initially then stranger' is the wordplay.
'initially' says to take the initial letters.
'then' says to put letters next to each other.
'stranger' becomes 'odder' (I've seen this before).
The initial letter of 'friend' is 'f'.
'f'+'odder'='FODDER'
(Other definitions for fodder that I've seen before include "Animal feed" , "Straw to eat" , "Food for animals" , "Food for horses or cattle" , "Bulk feed for livestock" .)