Word of the Day : February 28, 2019


noun BILL-yun

What It Means

1 US : a number equal to 1,000 million; also, British : a thousand milliard

2 : a very large number


If you were to count to a billion at the rate of one number per second, it would take you over 31 and a half years to finish.

"White dwarf stars start off extremely hot, but they no longer generate their own energy. And while they initially radiate enough heat that we can see them in our telescopes, they slowly lose their energy over billions of years." — Deborah Netburn, The Bismarck (North Dakota) Tribune, 15 Jan. 2019

Did You Know?

How much is a billion? It might depend on whom you ask. Billion was borrowed from French in the late 1600s to indicate the number one million raised to the power of two, or a million million—a number represented by a 1 followed by 12 zeros. However, the French later changed their naming conventions so that a billion became a thousand million (a 1 followed by 9 zeros) and a trillion became a thousand thousand million (or a million million, the old billion). The French have since returned to the older system, but it was this new system that was adopted by American English speakers in the 1800s. In Britain, the newer system has seen increasing use since the 1950s, but the older sense is still sometimes used there as well.

Test Your Vocabulary

What is the name for an explosion of a star in which the star may reach a luminosity one billion times that of the sun?



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