Wikipedia gives the Hanyu Pinyin spelling of the Chinese dumpling name jiaozi as jiǎozi.
The spelling uses tone marks: the caron over “ǎ” marks the third tone in standard Mandarin. The final syllable is written “zi” without a tone mark because it is pronounced with a neutral tone in this form. In ordinary English writing, the tone marks are often omitted, producing “jiaozi,” but jiǎozi is the precise Pinyin form.
Jiaozi is written 饺子 in simplified Chinese and 餃子 in traditional Chinese. The word refers to Chinese dumplings made with a dough wrapper and fillings such as pork, vegetables, seafood, or other ingredients. They may be boiled, steamed, pan-fried, deep-fried, baked, or served in soup.
The spelling is sometimes confused with related dumpling names. Wontons have thinner wrappers and are commonly served in broth, while guōtiē refers to a northern Chinese dumpling style often translated as “potstickers.” Japanese gyōza is a related Japanese version of jiaozi.