[a. F. billion, purposely formed in 16th c. to denote the second power of a MILLION (by substituting BI- pref.2 for the initial letters), trillion and quadrillion being similarly formed to denote its 3rd and 4th powers. The name appears not to have been adopted in Eng. before the end of the 17th c.: see quot. from Locke. Subsequently the application of the word was changed by French arithmeticians, figures being divided in numeration into groups of threes, instead of sixes, so that F. billion, trillion, now denote not the second and third powers of a million, but a thousand millions and a thousand thousand millions. Eng. retains the original and etymological use.]

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  1.  In Great Britain: A million millions. (= Fr. trillion.)

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1690.  Locke, Hum. Und., II. xvi. 86. But to shew how much distinct Names conduce to our well reckoning,… let us set all these following Figures in one continu’d Line…

        Nonillions.  Octillions  …  Trillions.  Billions.  Millions.  Units
857324.  162486  …  235421.  261734.  368149.  623137.
  The ordinary way of naming this Number in English, will be the often repeating of Millions, of Millions, of Millions, [etc.].

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a. 1711.  Ken, Prepar., Poet. Wks. 1721, IV. 67. A Star … will run, Of Miles a Billion round the Sun.

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1778.  Maseres, in Phil. Trans., LXVIII. 897. A billion, or the square of a million.

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1870.  Proctor, Other Worlds, ix. 200. The aggregate weight of the various meteoric systems … must be estimated by billions of tons.

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  2.  In U.S. (as in France): A thousand millions.

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1864.  See Webster, s.v. Numeration.

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