number one


Definition of number one

 (Entry 1 of 2)

1 : one's own interests or welfare : oneself looking out for number one often written No. 1
2 : one that is first in rank, importance, or influence often written No. 1

number one


Definition of number one (Entry 2 of 2)

1 : first in rank, importance, or influence : foremost cancer is the country's number one killer often written No. 1
2 : of highest or of high quality

Keep scrolling for more

Examples of number one in a Sentence

Noun Who's number one in this office? Getting the car fixed is number one on my list of priorities. I'll tell you why we can't go on a vacation: number one, we can't afford it, and number two, we'll miss my sister's party. Her movie is currently number one at the box office. When the goal was scored, the fans started to chant, “We're number one, we're number one.” I've been taking care of other people for too long. It's time for me to take care of number one. Adjective The book is the company's number one seller. Rule number one is don't get caught! He's public enemy number one: the nation's most wanted criminal.
See More
Recent Examples on the Web: Adjective This year another Vermont city, Killington, is number one. Michael Kolomatsky, New York Times, "Where’s the Best Place to Buy a Winter Vacation Rental?," 2 Jan. 2020 Carey's song was released in 1994 and spent time in the number one spot in the 90's, the 2000's, the 2010's and now the 2020's. Rasha Ali, USA TODAY, "Mariah Carey is the first artist to have a No. 1 song span four decades on Billboard's Hot 100," 31 Dec. 2019 The album hit the number one spot in several countries including the U.S. and his home of the UK. Jasmine Gomez, Seventeen, "Harry Styles' Net Worth Will Make You Crave Some "Watermelon Sugar"," 19 Dec. 2019 It’s no surprise the number one gallery is the helmet swinging fight between Browns’ Myles Garrett and Steelers’ Mason Rudolph. Josh Gunter And John Kuntz, cleveland, "’s top 10 most viewed photo galleries in 2019," 24 Dec. 2019 Styles also landed number one on the Rolling Stone Top 200 Albums Chart. Chloe Melas, CNN, "Harry Styles' 'Fine Line' album hits number one," 23 Dec. 2019 As Grande stans know, Sweetener was the artist's third album to hit number one on the Billboard charts. Leah Prinzivalli, Allure, "Ariana Grande Commemorated Sweetener With a Teeny Tattoo," 18 Dec. 2019 It was cited by the Wall Street Journal as first ever 100 percent digitally recorded and produced song to reach number one. Jordan Runtagh,, "Legendary Songwriter Desmond Child Reveals the Tales Behind Hits by Bon Jovi, Katy Perry and More," 25 Oct. 2019 CovCath was ranked number one in the state at the time. James Weber,, "Covington Catholic, Highlands football: 'It's our big game. It's the focus of our season.'," 15 Oct. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'number one.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of number one


circa 1705, in the meaning defined at sense 1


1839, in the meaning defined at sense 1

Keep scrolling for more

Learn More about number one

Time Traveler for number one

Time Traveler

The first known use of number one was circa 1705

See more words from the same year

Statistics for number one

Cite this Entry

“Number one.” The Dictionary, Merriam-Webster Inc., Accessed 27 January 2020.

Keep scrolling for more

More Definitions for number one

number one


English Language Learners Definition of number one

 (Entry 1 of 2)

: a person, thing, or position that is highest in rank : the most important person or thing in a group of people or things
: the most successful person or thing in a group of people or things
: your own happiness, health, or success

number one


English Language Learners Definition of number one (Entry 2 of 2)

: highest in rank or importance

More from Merriam-Webster on number one

Thesaurus: All synonyms and antonyms for number one

Comments on number one

What made you want to look up number one? Please tell us where you read or heard it (including the quote, if possible).


one that suddenly gains wealth or power

Get Word of the Day daily email!

Test Your Vocabulary

Intact Latin Quiz

  • roman tablet
  • What did focus mean in Latin?
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!