What is mien? How to use in English

The word "mien" originated from the Old French word "men," which meant "countenance" or "expression." In Middle English, this word evolved into "myn," which was used to describe the facial expression or appearance of a person. The modern-day term "mien" is of Chinese origin, specifically from the Mandarin Chinese word "xìn," which marked a distinctive change in the meaning of the word. "Xìn" refers to one's demeanor, behavior, or attitude, irrespective of one's facial expression or appearance. In modern terminology, "mien" is defined as the manner, bearing, or demeanor that characterizes a particular individual or group; it may indicate social or emotional status, occupation, or cultural heritage. While the use of "mien" continues to be widespread in certain dialects of American English, markedly in the southern United States, it has fallen somewhat out of favor in Standard English.