Pronunciation: (siks'tē-thûrd'), [key]
1. next after the sixty-second; being the ordinal number for 63.
2. being one of 63 equal parts.
1. a sixty-third part, esp. of one (1/63).
2. the sixty-third member of a series.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.