The Korean name listed for jiaozi in Wikipedia’s language table is mandu.
Mandu is the Korean term for dumplings in Korean cuisine. Wikipedia lists the Korean name in Hangul as 만두, with the romanized form “mandu.” Although Korean mandu and Chinese jiaozi are related, mandu is a broader Korean food category that includes several shapes, fillings, and cooking methods.
Mandu may be steamed, boiled, pan-fried, or deep-fried. Examples include gun-mandu, which is pan-fried; jjin-mandu, which is steamed; and mul-mandu, which is boiled. Manduguk is a soup made with mandu in broth, showing how the same dumpling family can appear in a soup without being classified simply as soup.
The relationship among jiaozi, gyōza, and mandu often causes confusion. Jiaozi is the Chinese term, gyōza is the Japanese term for a related style, and mandu is the Korean term. Their histories and culinary traditions overlap through regional exchange, but the names identify different national food traditions.
Mandu has also been part of Korean royal cuisine and is now common in restaurants, supermarkets, and street-food venues throughout Korea.