Salvation Army practice to provide something to eat (7)
I believe the answer is:
sausage
'something to eat' is the definition.
(sausage is a kind of food)
'salvation army practice' is the wordplay.
'salvation army' becomes 'SA' (abbreviation).
'practice' becomes 'usage' (usage is a kind of practice).
'sa'+'usage'='SAUSAGE'
'to provide' acts as a link.
(Other definitions for sausage that I've seen before include "E.g. salami, bratwurst" , "Assuage (anag.)" , "Banger; snag" , "BBQ food?" , "Not a - means nothing" .)