yo
interj.— «Yo! Call used to attract dealers attention to bundles flung from trucks.» —“Mail and Newspaper Delivery Workers’ Slang and Jargon” by Individual delivery workers at Park Row, New York City in New York City Lexicon of Trade Jargon , 1938-39. (source: Double-Tongued Dictionary)
Further reading
If you speak a second or third language, you may remember the first time you dreamed in that new tongue. But does this milestone mean you’re actually fluent? And a couple’s dispute over the word regret: Say you wish you’d been able...