number one

noun

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

adjective

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

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.
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Recent Examples on the Web: Adjective

From Russian president Vladimir Putin playing the anthem on the piano to Ross, Joey and Chandler dancing to the number one hit in their living room. SI.com, "How Social Media Helped Create a Positive Atmosphere for England to Thrive in During World Cup Run," 12 July 2018 Model Chanel Iman may be husband and New York Giants wide receiver Sterling Shepard’s number one fan now, but in just a few months, the NFL star is going to have another lady sitting on the sidelines cheering him on at football games. Kaitlyn Frey, PEOPLE.com, "Chanel Iman on Expecting a Baby Girl: 'I'm Dying to Put Her in a Cheerleading Outfit!'," 10 July 2018 The Brazilian number one endured a poor World Cup, where his side were defeated in the quarter finals to Roberto Martinez's Belgian side. SI.com, "Roma Linked With AC Milan Forward Suso as Rossoneri Look to Ease Financial Worries," 13 July 2018 Our students’ well-being is our number one priority, as USC remains committed to providing an unparalleled education, complete with world class faculty, cutting-edge research opportunities, and an engaging campus environment. Alex Bhattacharji, Town & Country, "Can USC Survive Scandal and Shed Its Spoiled-Kid Reputation Once and For All?," 10 July 2018 His latest album, entitled '?', debuted at number one on the Billboard 200. Monique O. Madan, Alex Harris, Carli Teproff And Rebecca Ellis, miamiherald, "Rapper XXXTentacion shot dead outside South Florida motorcycle shop," 19 June 2018 Watch the gospel group's performance of Stand By Me, which has since gone to number one on the Billboard charts, below. Caroline Hallemann, Town & Country, "Prince Charles Shared a Sweet Moment with the Conductor of the Kingdom Choir at Today's Garden Party," 5 June 2018 In terms of the world's biggest music markets, there's no change with the U.S. still at number one, followed by Japan, Germany and the U.K. Richard Smirke, Billboard, "IFPI Global Report 2018: Music Sales Rise for Third Straight Year as Streaming Becomes Biggest Revenue Source," 24 Apr. 2018 Hey, Mary Kay: Please Browns brass DO NOT let the mock draft experts influence you into a quarterback pick at number one. Mary Kay Cabot, cleveland.com, "Is it Sam Darnold or Josh Allen for the Browns after their Pro Days? Hey, Mary Kay!," 25 Mar. 2018

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.

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First Known Use of number one

Noun

circa 1705, in the meaning defined at sense 1

Adjective

1839, in the meaning defined at sense 1

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The first known use of number one was circa 1705

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More Definitions for number one

number one

noun

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

adjective

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

: highest in rank or importance

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