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

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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

The holders and number one ranked team in the world were the very last of the first round of group matches and had already seen all of their potential rivals for the trophy in action. SI.com, "USWNT's 13-0 Win Over Thailand Was Incredible, But No Answer to the Questions That Remain," 12 June 2019 Robocalls are one of the few issues the FCC is totally aligned on — the unwanted calls are by far the number one issue consumers file complaints about. Nilay Patel, The Verge, "Robocalls can now get blocked by your carrier by default," 6 June 2019 And people are playing more too: Basketball is the second-most popular sport in the country, and number one among young girls, with immigrants opting to put their kids in basketball over hockey. refinery29.com, "The Raptors Shaped My Identity — Now They're Re-Shaping All Of Canada's," 6 June 2019 Last year's number one suburb, Montgomery, fell to number seven this year as a result of a lower education ranking and median home sale price. Maia Anderson, Cincinnati.com, "What's the best Cincinnati suburb? It's Madeira, magazine says," 5 June 2019 The release of Map of the Soul: Persona marked the group's third number one on the chart making them the first group since the Beatles to do so in less than one year. Jasmine Gomez, Seventeen, "10 Facts About BTS That Will Make You Want To Join The ARMY," 5 June 2019 The Deebot is Amazon's number one best-selling robot vacuum, boasting thousands upon thousands of glowing customer reviews. Rebekah Lowin, Country Living, "The Number One Best-Selling Robot Vacuum on Amazon Is Nearly 50% Off Today," 9 May 2019 It was ranked number one in the nation in income mobility and median student income by age 34 ($52,200) in a 2017 study by a team from Harvard, UC–Berkeley, and Brown universities. Chuck Thompson, Popular Mechanics, "The State of American Trade Schools," 13 Mar. 2019 Meanwhile, Beyonce’s dermatologist Harold Lancer told THR that liposuction is the number one cosmetic procedure, adding that big butts are less popular now. Lifted nose tips, Lancer added, are also a new trend. Lindsay Weinberg, The Hollywood Reporter, "Vaginal Rejuvenation Is the Latest Cosmetic Trend to Hit Hollywood," 12 July 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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Time Traveler for number one

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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