In the 1820s and '30s, the American Southwest was rough-and-tumble territory—the true Wild West. English-speaking cowboys, Texas Rangers, and gold prospectors regularly rubbed elbows with Spanish-speaking vaqueros in the local saloons, and a certain amount of linguistic intermixing was inevitable. One Spanish term that caught on with English speakers was vamos, which means "let's go." Cowpokes and dudes alike adopted the word, at first using a range of spellings and pronunciations that varied considerably in their proximity to the original Spanish form. But when the dust settled, the version most American English speakers were using was vamoose.
Recent Examples on the WebKhan’s group packed fast and vamoosed on a small airplane, which rose straight into a thrashing thunderstorm. David Quammen, The New Yorker, 4 May 2020 Nearby, a woman was making her own bathroom right next to the entrance of a residential building, vamoosing only when the doorman, Clever Santos Chavez, chased her away.Washington Post, 24 Feb. 2020 In November, the owner of the building housing Trump’s SoHo hotel in Manhattan paid the Trump Organization to vamoose. Chas Danner, Daily Intelligencer, 27 Jan. 2018 The Senate left town for its August recess Thursday, a week after the House vamoosed, and let’s hope the Members get an earful from constituents at home. The Editorial Board, WSJ, 4 Aug. 2017
Word History
Etymology
borrowed from Spanish vamos "let us go," suppletive 1st person plural imperative (going back to Latin vadimus, 1st person plural present indicative of vadere "to proceed, go") of ir "to go," going back to Latin īre — more at wade entry 1, issue entry 1