Suffer in South American train, right away (7)
I believe the answer is:
sustain
'suffer' is the definition.
('sustain' can be a synonym of 'suffer')
'south american train right away' is the wordplay.
'south american' becomes 'sus' (I've seen this in other clues).
'right' becomes 'r' (common abbreviation).
'away' indicates named letters should be taken away.
'train' with 'r' removed is 'tain'.
'sus'+'tain'='SUSTAIN'
'in' is the link.
(Other definitions for sustain that I've seen before include "Give food to" , "Maintain" , "Strengthen, support" , "Bear (something's weight)" , "Undergo" .)