Definition of "thousandth"

thousandth

/ˈθaʊzəndtθ/

adjective
not comparable
1. The ordinal numeral form of one thousand; last in order of a series of a thousand; next after the nine hundred and ninety-ninth.
noun
plural thousandths
1. (singular only) The person or thing in the thousandth position.
2. One of a thousand equal parts of a whole.
  Quotations
  “Ah, Alan,” murmured Dorian, with a sigh, “I wish you had a thousandth part of the pity for me that I have for you.”
  1891, Oscar Wilde, chapter XIV, in The Picture of Dorian Gray, London, New York, N.Y., Melbourne, Vic.: Ward Lock & Co., page 256