blue Billy

In real, traceable use. Part of the curated seed collection; community review is coming.

Sense 1

Meaning · English

The refuse ammoniacal lime from gas factories.

Register: slang

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).

Sense 2

Meaning · English

the handkerchief (blue ground with white spots) sometimes worn and used as a colour at prize-fights. Also, the refuse ammoniacal lime from gas factories.

Era: ca. 1874 (Victorian)

Where it’s used: Origin British & Irish English
Sources & notes

Historical definition reproduced from Hotten’s The Slang Dictionary (1874, public domain; Project Gutenberg #42108, retrieved 2026-07-31). Reflects the attitudes of its era.

Common questions

What does “blue Billy” mean?

The refuse ammoniacal lime from gas factories.

Is “blue Billy” formal or informal?

blue Billy is generally slang.