quadrillion

Etymology

From French quadrillion, from quadri- (“four”) + -illion.

num

1. (US, modern British and Australian, short scale) A thousand trillion (logic: 1,000 × 1,000^4): 1 followed by fifteen zeros, 10¹⁵.
   Integrating data from all continents and major biomes, we conservatively estimate 20 × 10¹⁵ (20 quadrillion) ants on Earth, with a total biomass of 12 megatons of dry carbon. 19 Sept 2022, P. Schultheiss et al., “The abundance, biomass, and distribution of ants on Earth”, in Proceedings of the National Academy of Sciences of the United States of America, page 1, column 2
2. (dated, UK, Australia, long scale) A million trillion (logic: 1,000 × 1,000,000^2): 1 followed by twenty-four zeros, 10²⁴.

noun

1. (figurative, slang, hyperbolic) Any very large number, exceeding normal description.
   They'd never understand — not in a quadrillion years. 1999, Beverly Lewis, A Perfect Match, Bethany House Publishers, page 23
   Me, I never refuse a meal, and believe me I seen some heavy weather. I musta flown a quadrillion miles and I never did have a problem. 2000, J. D. Maples, Trojan Steers, Lomaland Books Inc, page 58
   The sky is so absolutely clear with a quadrillion stars. 2004, Arthur Kopecky, New Buffalo: journals from a Taos commune, UNM Press, page 143
   She's named after this famous singer from a quadrillion years ago. 2006, Evelyn Caro, The Flickering Attic Window, Trafford Publishing, page 8