eight•i•ethPronunciation: (ā'tē-ith), [key]
next after the seventy-ninth; being the ordinal number for 80.
being one of 80 equal parts.
an eightieth part, esp. of one (1/80
the eightieth member of a series.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.