- next after the thirtieth; being the ordinal number for 31.
- being one of 31 equal parts.
- a thirty-first part, especially of one (1/31).
- the thirty-first member of a series.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for thirty-first
Howe's reinforcements had reported for duty by the thirty-first of December.
This beautiful volume is printed from the thirty-first London edition.
Lastly, Mr. Onions Winter was advertising the thirty-first thousand of that work.A Great Man
“The thirty-first of December at half-past eight,” explained Betty.Betty Wales Senior
The Thirty-first held its ground; but yielding was only a question of time.From Fort Henry to Corinth
Manning Ferguson Force