tai chi (t?? ch??, j??) or tai chi chuan (chwän?)n. A Chinese martial art whose system of physical exercises is often practiced as a way of meditating or improving well-being.[From Mandarin tài jí quán (formerly romanized t’ai chi ch’üan) : tài jí, great ultimate (a concept in Chinese cosmology) (from Middle Chinese thaj` k?i??k : thaj`, very great, greatest + k?i??k, ridge-pole, pole, extremity) + quán, boxing (from Middle Chinese k?yan, fist).]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.