for•ti•ethPronunciation: (fôr'tē-ith), [key]
next after the thirty-ninth; being the ordinal number for 40.
being one of 40 equal parts.
a fortieth part, esp. of one (1/40
the fortieth member of a series.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.