Pronunciation: (ā'tē fûrst'), [key]
1. next after the eightieth; being the ordinal number for 81.
2. being one of 81 equal parts.
1. an eighty-first part, esp. of one (1/81).
2. the eighty-first member of a series.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.