oy

The interjection 'oy' is a loanword from Yiddish, which itself borrowed it from the Old High German exclamation 'oi', 'auwei', or 'owē', expressions of pain, grief, or alarm. These Germanic cries are ultimately of onomatopoeic origin, imitating a sudden vocal outburst. Entering American English primarily through Yiddish-speaking Ashkenazi Jewish communities in the early 20th century, 'oy' has been adopted into broader informal use to convey a wide range of emotions, from mild irritation to profound exasperation, while retaining its core function as an emotive interjection.

This is a simplex word (an interjection) borrowed into English. It does not contain separable morphemes in the modern English spelling.