abaddon

UK C19. From Abaddon, from Middle English, from Late Latin, from Ancient Greek Ἀβαδδών (Abaddṓn, “Abaddon”), from Hebrew אבדון‎ (ābaddōn, “destruction, abyss”), from אבד‎ (ābad, “to be lost, to perish”).

abaddon (plural abaddons)

1. (archaic, British slang) An informer; a criminal who informs on other criminals to the authorities.
   • c. 1839, Report of the Trial of the Great Gold Dust Robbery:

     The prisoner, Money Moses, better known among thieves and fences as Moses the abaddon, has been, to my knowledge, for the last twenty years a receiver and dealer in stolen property.

• grass, nark, stool pigeon, see Thesaurus:informant

• Albert Barrère and Charles G[odfrey] Leland, compilers and editors (1889–1890), “abaddon”, in A Dictionary of Slang, Jargon & Cant […], volume I (A–K), Edinburgh: […] The Ballantyne Press, →OCLC, page 2.
• Farmer, John Stephen (1890) Slang and Its Analogues‎, volume 1, page 3