饺 is almost exclusively used in 饺子 (dumpling). 包饺子 (make dumplings) is a beloved family activity, especially during Spring Festival.
culture
饺子 are eaten during Chinese New Year because their shape resembles ancient gold ingots (元宝), symbolizing wealth. In northern China, making dumplings together is the quintessential New Year family activity.
饣 is the left-side form of 食 and marks 饺 as something edible. Same radical heads almost every food word: 饭 rice, 饼 pancake, 馆 restaurant, 馒 steamed bun. Dumplings sit comfortably in this family.
交 gives the sound jiāo to jiǎo (tone shift to third). There's a folk-etymology nod to "crossed edges" of a dumpling fold, but most linguists treat 交 here as pure phonetic. Same phonetic in 校 xiào, 较 jiào, 郊 jiāo.
