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

Take your number one to an old-school game center and duel to win each other a V-Day gift. Kelsey Stiegman, Seventeen, "14 Cheap Valentine's Day Date Ideas That Are Actually Fun," 19 Nov. 2018 One of the number one reactions to PTSD is isolation. Christopher Carbone, Fox News, "Nonprofit teaches farming to vets, helps to reintegrate them into civilian life," 2 Oct. 2018 Apple just removed its number one paid utility in the Mac App Store, Adware Doctor, after it was found to be secretly recording users’ app data and browser history and sending it back to a server located in China, as spotted by 9to5Mac. Shannon Liao, The Verge, "Apple removes a top paid utility app that stole data and sent it back to China," 7 Sep. 2018 Students beginning their semester at MIT have reason to celebrate—the Massachusetts university was just named the number one school in the country. Sam Dangremond, Town & Country, "The 10 Best Colleges in America Are...," 27 Aug. 2018 Texas is currently the number one state in terms of crude oil and natural gas consumption, as well as the sixth in terms of coal consumption. David Grossman, Popular Mechanics, "Texas Could Easily Generate Most of Its Energy Through Wind And Solar, Study Finds," 3 Jan. 2019 The number one design tenant of this style is to bring the glam. Sienna Fantozzi, House Beautiful, "Everything You Need To Know About Hollywood Regency Design," 30 Nov. 2018 The results were that better module efficiency was the number one cause of declines in solar panel cost per watt between 1980 and 2012, with money from government and private research and development contributing to the bulk of those efficiencies. Megan Geuss, Ars Technica, "How the falling cost of solar panels can teach us to make new tech affordable," 26 Nov. 2018 At Frito-Lay, food safety is always our number one priority, and our snacks meet all applicable food safety regulations as well as our rigorous quality standards. Fox News, "Tennessee teen's love of spicy snacks led to gallbladder removal, mom claims," 2 Oct. 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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