Tons perishing in Turin, caught by side of Po River (7)
I believe the answer is:
orinoco
'river' is the definition.
(I know that Orinoco is a river)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for orinoco that I've seen before include "Colombia/Venezuela river" , "South American river - lazy Womble" , "large flow of water" , "O, I croon about the river" , "Common character" .)