South American greeting Japanese food (5)
I believe the answer is:
sushi
'japanese food' is the definition.
(sushi is a type of Japanese food)
'south american greeting' is the wordplay.
'south' becomes 's' (abbreviation).
'american' becomes 'US' (abbreviation for United States).
'greeting' becomes 'hi' (hi is a kind of greeting).
's'+'us'+'hi'='SUSHI'
(Other definitions for sushi that I've seen before include "Fated" , "Food from Japan" , "put away in Japan" , "Asian food" , "Rice, seafood cuisine" .)