Banker is partly Maori? No, Columbian (7)
I believe the answer is:
orinoco
'banker' is the definition.
(I've seen this before)
'partly maori? no columbian' is the wordplay.
'partly' indicates a hidden word (part of the clue is used).
'ORINOCO' is hidden within 'maori no columbian'.
'is' is the link.
(Other definitions for orinoco that I've seen before include "River of South America" , "South American river flowing into the Atlantic" , "South-American river" , "Great river flowing through Venezuela to Atlantic" , "River, rising in Venezuela, forming part of its border with Colombia and flowing into the Atlantic" .)