Definition of "quadrillionth" []

• The ordinal number matching the number quadrillion in a series. (noun)
• One of a quadrillion equal parts. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The reason was not narrow-mindedness, but incompatible technology: the length of the waves in the whole electromagnetic spectrum of light range from gamma rays that are the size of the nucleus of an atom, a quadrillionth of a meter, to radio waves measured in meters; as a result, the telescopes for each band of wavelengths must be wildly different."
• "So Quentin is bored and miserable except when he hides in his closet re-reading Fillory and Further for the quadrillionth time."
• "Femto is a decimal prefix that denotes one quadrillionth."