Hi again, good to see you came back to ask more questions and we didnt scare you off!
The Chinook is named after a native american (red indian) tribe! In fact lots of american helicopters get named after american tribes, like the Chinook, The Apache gunship, and the Comanche.
The americans like to do things like that, like their fighter planes which are all named after different types of animal (They have fighters called the Falcon, The eagle, the tomcat and the hornet, and there are loads more!).