thirty-first

[ thur-tee-furst ]

adjective

1. next after the thirtieth; being the ordinal number for 31.
2. being one of 31 equal parts.

noun

1. a thirty-first part, especially of one (1/31).
2. the thirty-first member of a series.

Example Sentences

Finland's application was processed in record time and it became the thirty-first member of the alliance earlier this month.

From Reuters

“Yes, of course. We will be out by December thirty-first, maybe earlier. Again, I’m sorry, Mr. Beiderman. I hope you have a happy holi—” Papa stopped and looked down at the phone screen.

From Literature

He was able to sustain the sobriety for one month but went right back to hitting the bottle on the thirty-first day, the article said.

From Fox News

Thus, every time you play “Disc 2: High Rise” you start on the thirty-first floor of a building and must make you way down.

From Washington Post

Is it the thirty-first day of that month?

From The New Yorker