This means describing a woman's figure is very good, there is no excess fat at the waist, and the waist-to-body ratio is soft and elastic. In the field of fitness, fairy waist is used to describe the very slender state of female waist. On social media, immortal waist is also used to describe some people's body characteristics. A person's waist is narrow enough to accommodate an adult standing. Fairy waist is also an expression of praise, which is used to describe someone's good figure, especially the beautiful waist line. Fairy waist is a kind of commendatory term, which is used to praise the figure of people around you.