The story
From boring + billion. From the remarkably stable environment of the time, over a period of 1 billion years, from climate, weather, geology, tectonic shifting, lifeforms.
Etymology from Wiktionary, CC BY-SA 4.0.
Boring Billion
Today it means: The period of time from 1.8 Gya to 800 Mya, on Earth, lying in the middle of the Proterozoic. Full definition →