Poems on South American port (6)
I believe the answer is:
odessa
'port' is the definition.
(I've seen this before)
'poems on south american' is the wordplay.
'poems' becomes 'odes' (ode is a kind of poem).
'on' means one lot of letters go next to another.
'south american' becomes 'sa'.
'odes'+'sa'='ODESSA'
(Other definitions for odessa that I've seen before include "Ukrainian location" , "Ukrainian Black Sea port" , "Seaport" , "Black Sea location" , "Do seas come into Ukrainian city?" .)