Some visit Argentina, returning for free (6)
I believe the answer is:
gratis
'free' is the definition.
('gratis' can be a synonym of 'free')
'some visit argentina returning' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'returning' is a reversal indicator.
'sitarg' is hidden within 'visit argentina'.
'sitarg' backwards is 'GRATIS'.
'for' is the link.
(Other definitions for gratis that I've seen before include "Without charge" , "Free of charge" , "On the house" , "Free (Latin)" , "Without payment" .)