Que·chan (k?ch??n, kw?t?sän?)n. pl. Quechan or Que·chan 1. A member of a Native American people inhabiting an area along the lower Colorado River in Arizona and California.2. The Yuman language of the Quechan. In both senses also called Yuma.[Quechan kwa??n, those who descended (from the sacred mountain of creation).]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.