thirty-first

1 of 2

adjective

1

: being number 31 in a countable series

the thirty-first day

see Table of Numbers

2

: being one of 31 equal parts into which anything is divisible

a thirty-first share of the money

thirty-first

2 of 2

noun

"

1

: number 31 in a countable series

the thirty-first of the month

2

: the quotient of a unit divided by 31 : one of 31 equal parts of anything

one thirty-first of the total

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now