Oi /ɔɪ/ is an interjection used in various varieties of the English language, particularly British English, Australian English, New Zealand English, Canadian English, Irish English, Singaporean English and Southern African English, as well as Hindi and Japanese to get the attention of another person or to express surprise or disapproval.
"Oi" has been particularly associated with working class and Cockney speech. It is effectively a local pronunciation of "hoy" (see H-dropping), an older expression. A study of the Cockney dialect in the 1950s found that whether it was being used to call attention or as a challenge depended on its tone and abruptness. The study's author noted that the expression is "jaunty and self-assertive" as well as "intensely cockney".
A poll of non-English speakers by the British Council in 2004 found that "oi" was considered the 61st most beautiful word in the English language. A spokesman commented that "Oi is not a word that I would've thought turned up in English manuals all that often." "Oi" was added to the list of acceptable words in US Scrabble in 2006.
According to Friedrich Nietzsche, in Greek, "oi" was an expression of pain, and someone who was in pain or miserable was said to be "oizuros". In Latin, the similar "oiei" was a cry of pain. Coincidentally, the term oi () in informal Japanese is used in the same way as British English, typically by older men to subordinates; an elongated ōi is used when someone is at a distance. Also, in Portuguese, "oi!" [oɪ] means "hi" - mostly in Brazil, as people in Portugual use "olá " instead, still, under the exclusively Brazilian usage, the interrogative "oi?" can be used in the sense of "what did you say?", sometimes showing disapproval or mistrust of something said previously, or "yes?", generally when answering the telephone or intercom (Portuguese people usually say "está?" on the phone). In accents of rural central Iranian Persian language and Luri language, "oi' (Persian: اوی) has the same usage as in English. In India, "oi" is also used as an exclamation in various contexts. For example it can be used to call someone some distance away, as a way of showing aggression, or when someone is surprised. In Russian, "oy" ("ой") is often used as an expression of various degrees of surprise. In the Scandinavian languages, "Oi!" or the Swedish variant, "Oj!", is commonly used. Here it means "Oh" or "Woops", an exclamation of surprise. There's also a form in Indonesian "oi" means to call someone.