begone

What it means

1. archaichumoroususuallyExpressing a desire or a command for someone or something to go away.

   Fairies be gone, and be alwaies away.

   c. 1595–1596 (date written), William Shakespeare, “A Midsommer Nights Dreame”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene i], page 157, column 1

   2 more examples

   "Begone! move quickly! if quickly you can, you that shine forth into sight in moist times like the worm."

   1856, Herman Melville, The Lightning Rod Man

   Begone. Thus decrees Unicron, Chaos-Bringer!

   2023 December 18, “Galactus VS Unicron (Marvel Comics VS Transformers)” (14:21 from the start), in DEATH BATTLE!, season 10, episode 16, spoken by Unicron (Brent Mukai)

In a sentence

Fairies be gone, and be alwaies away.

c. 1595–1596 (date written), William Shakespeare, “A Midsommer Nights Dreame”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene i], page 157, column 1

Where it comes from

Univerbation of be + gone. Compare English beware.