Qinghai Lake also Ko·ko Nor (k??k?? nôr?) A salt lake of north-central China west of Xining. The largest lake in China, it is at an altitude of about 3,200 m (10,500 ft).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.