Pronunciation: (thûr'tē-wun'), [key]
1. a cardinal number, 30 plus 1.
2. a symbol for this number, as 31 or XXXI.
3. a set of this many persons or things.
amounting to 31 in number.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.