So gutted, having killed American — getting put away (7)
I believe the answer is:
scoffed
'put away' is the definition.
(both can mean swallowed or ate)
'so gutted having killed american' is the wordplay.
'so' becomes 'sic' ('so' in Latin).
'gutted' says to hollow out the word (remove centre letters) (to gut something is to remove its insides).
'having' is a charade indicator (letters next to each other).
'killed american' becomes 'offed' (US term meaning murdered).
'sic' with its middle taken out is 'sc'.
'sc'+'offed'='SCOFFED'
'getting' is the link.
(Other definitions for scoffed that I've seen before include "Showed no respect - ate greedily" , "Expressed scorn" , "Laughed at with contempt and derision" , "Mocked" , "Jeered; ate" .)