Millionth

Part of speech: noun, adjective

Pronunciation: /ˈmɪljənθ/

Definitions

1. One part out of one million equal parts of a whole
2. A fraction representing one unit divided by one million
3. A very small quantity equal to one millionth of something

Etymology: The word is a simple formation: "million" plus the ordinal suffix "-th," the same ending that turns "four" into "fourth." The real interest lies in the older parts. "Million" came into English from Old French "million," which had been borrowed from Italian "milione," an augmentative of "mille" (thousand), so the sense is literally "a big thousand." The Italian form descends from Latin "mille," and the Latin word traces back to a very ancient root for "thousand" in Proto-Indo-European. Because "million" was a noun for a quantity before it was a number in its own right, adding "-th" creates an ordinal that names the position of one part among a million equal parts. The suffix appears in many ordinals, such as "hundredth" and "thousandth," so "millionth" follows an established pattern rather than a special one. The word is most often used for fractions, as in a one-millionth share of a total.

Synonyms: one-millionth, 0.000001, infinitesimal, smallest fraction, minute part