quadrillion Meaning, Definition & Usage

  1. noun the number that is represented as a one followed by 24 zeros
    • in England they call a septillion a quadrillion
  2. noun the number that is represented as a one followed by 15 zeros

WordNet

Quad*ril"lion noun
Etymology
F., fr. L. quater four times, akin to quattuor four, E. four; -- formed like million. See Four, Million.
Definitions
  1. According to the French notation, which is followed also upon the Continent and in the United States, a unit with fifteen ciphers annexed; according to the English notation, the number produced by involving a million to the fourth power, or the number represented by a unit with twenty-four ciphers annexed. See the Note under Numeration.

Webster 1913