from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The cardinal number equal to 1018.
- n. Chiefly British The cardinal number equal to 1030.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A billion billion: 1 followed by eighteen zeros, 1018.
- n. A million quadrillion: 1 followed by 30 zeros, 1030.
- n. Any very large number, exceeding normal description.
from The Century Dictionary and Cyclopedia
- n. In the English notation, the fifth power of a million, a unit followed by thirty ciphers; in the French notation, used generally in the United States, the sixth power of one thousand, a unit followed by eighteen ciphers.
- Noting a quintillion; the cardinal numeral corresponding to a quintillion: strictly a collective noun. See hundred, a.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the number that is represented as a one followed by 18 zeros
Latin quīntus, fifth; see penkwe in Indo-European roots + (m)illion.(American Heritage® Dictionary of the English Language, Fourth Edition)
quint- (“five”) + -illion; ie the fifth power of a million, 1030. (Wiktionary)