Entry: cognomen (n.)
In context: "Sober, she'd call him Bimmy or Bim because that's what she heard his little friends call him. She didn't know the neighborhood cognomen came from an acronym for 'Big Indestructible Moron.'"
In Latin use: (a) The third name, family name, or surname of a Roman citizen, as Marcus Tullius Cicero, Caius Julius Cæsar; (b) an additional name or epithet bestowed on individuals, as Africanus, Cunctator (in later Latin called agnomen).
but more accurately here:
Hence, in English use: a distinguishing name or epithet given to a person or assumed by himself; a nickname.
SNOOT score: 2
Source: Oxford English Dictionary