Definition of "billion"

At the last assessment it [the national debt] amounts to seven billion pounds (£7,000,000,000).

1921 January 24, “National Finances”, in Devon and Exeter Gazette, page 5

In America alone, people spent $170 billion on “direct marketing”—junk mail of both the physical and electronic varieties—last year. Yet of those who received unsolicited adverts through the post, only 3% bought anything as a result.

2013 May 25, “No hiding place”, in The Economist‎, volume 407, number 8837, page 74

However, despite the prospect of HS2 being curtailed and the revelation that the programme is late and billions over budget, for now, at least, work on the scheme appears to be business as usual

2019 October, Dan Harvey, “HS2 costs rise as schedule slips”, in Modern Railways, page 9

The ChatGPT service which serves as Web front-end to GPT-3.5 and GPT-4 was the fastest-growing service in history to break the 100 million user milestone in January and had 1 billion visits by February 2023.

2023 October 30, Herbold et al., “A large-scale comparison of human-written versus ChatGPT-generated essays” (18617), in Scientific Reports, volume 13, page 1

n = 1,000,000,000,000, that is, = a billion, or the square of a million

1778, Francis Maseres, “A Method of Finding, by the Help of Sir Isaac Newton's Binomial Theorem, a Near Value of the very Slowly Converging Infinite Series [...]”, in Philosophical Transactions of the Royal Society‎, volume lxviii, number xli

There is a bill to be picked up for cleaning the former Soviet countries of £1 billion. By that I mean a British billion, because when I was little I was told that a billion was a million million and then the Americans said that it was a thousand million. Well, I am talking about a million million pounds worth of clean-up to be done.

2000 November 8, Stephen Ladyman, “[Speech to the House of Commons]”, in Hansard‎