1 number one | Definition of number one

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

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

After Lil Nas X propelled his viral TikTok hits into a record-breaking number one song and a major label deal, TikTok has another viral star: Stunna Girl. Melissa Locker, Time, "TikTok Star Stunna Girl Sparks the Flashy 'Runway' Challenge," 4 Sep. 2019 The number one issue is the initialization of the model. Katherine Ellen Foley, Quartz, "How to read the maps that predict hurricane paths," 30 Aug. 2019 The safety of our guests and crew is our number one priority and our ships will remain a safe distance from the storm at all times. Tonya Alanez, sun-sentinel.com, "Tropical Storm Dorian: Florida is in the cone and Puerto Rico is under a hurricane watch," 27 Aug. 2019 As always, the safety of our community is our number one priority. Kieran Nicholson, The Denver Post, "Man arrested in one of two fatal stabbings in Lakewood’s Belmar Park," 21 Aug. 2019 Signature item: The Beach Bowl is Rush Bowl’s number one seller. Kelly Wei, Dallas News, "When did açai bowls become all the rage, and where should you go in D-FW to find them? Curious Texas explores," 9 Aug. 2019 Men who come from a place where the number one film of the year (so far) is Avengers: Endgame, which touts toothless representation while failing spectacularly to go beyond standard-issue good and evil. Soraya Roberts, Longreads, "Won’t You Be My Neighbor: An Anti-Hate Pop Culture Syllabus," 9 Aug. 2019 Hydration will come courtesy of FIJI Water, the number one premium imported bottled water brand in the U.S. The water is back for a sixth consecutive year as the Official Water Partner of the 71st Emmy Awards Red Carpet and Governors Ball. Chris Gardner, The Hollywood Reporter, "Emmys: First-Look at the TV Academy's Governors Ball," 8 Aug. 2019 Not surprisingly the number one reason why most people install photovoltaic (PV) solar panels is to slash their electric bill. Joseph Truini, Popular Mechanics, "Is Going Solar Right for You?," 27 July 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

Noun

circa 1705, in the meaning defined at sense 1

Adjective

1839, in the meaning defined at sense 1

Keep scrolling for more

Keep scrolling for more

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

More from Merriam-Webster on number one

Thesaurus: All synonyms and antonyms for number one