nine•ti•ethPronunciation: (nīn'tē-ith), [key]
next after the eighty-ninth; being the ordinal number for 90.
being one of 90 equal parts.
a ninetieth part, esp. of one (1/90
the ninetieth member of a series.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.