Definition of thirty
- wrote thirty on the last page of the story
The temperature outside is in the high thirties.
He is in his thirties.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thirty.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
First Known Use: before 12th centurySee Words from the same year
What made you want to look up thirty? Please tell us where you read or heard it (including the quote, if possible).