Definition of "ninth"

ninth

/naɪnθ/

adjective
not comparable
1. The ordinal form of the number nine.
noun
plural ninths
1. The person or thing in the ninth position.
2. One of nine equal parts of a whole.
3. (music) The compound interval between any tone and the tone represented on the ninth degree of the staff above it, as between one of the scale and two of the octave above; the octave of the second, consisting of 13 or 14 semitones (called minor and major ninth).
verb
third-person singular simple present ninths, present participle ninthing, simple past and past participle ninthed
1. To lose a ninth.
  Quotations
  οὐ[δ̓] ὲνατεὐεται, should be translated “a tithe (offering or fee) is not given (or paid)”, “no tithing” (literally, “a ninth is not given”, “no ninth-ing”, if I may coin such a word).
  1973, Herakles on Thasos‎, page 79
  A yearling "is ninthed" for Semele on Myconos (LSCG 96.23–24); the victim "is not ninthed" for Heracles Thasios
  2010, Religion and Reconciliation in Greek Cities: The Sacred Laws of Selinus and Cyrene‎, page 161
2. To divide by nine.
  Quotations
  THE NINTHER-MEAN COMBINATION When data are only a little worse than usual, so far as wild and straggling values are concerned, we can do well enough by taking means of the results of ninthing.
  2014, Contributions to Survey Sampling and Applied Statistics: Papers in Honor of H.O Hartley‎