(idiom) Specifically referring to northern Jiangxi province or generally the middle and lower reaches of the Yangtze River; it is named for being at the upper reaches of the ancient state of 吴 wú and the lower reaches of the ancient state of 楚 chǔ

(idiom) Head in 吴 wú and tail in 楚 chǔ; describes two regions or things that are close together and overlap, where one starts where the other ends