one

1 of 4

adjective

ˈwən

: being a single unit or thing

one day at a time

She is one year old.

: being one in particular

early one morning

The Grand Canyon is one place I'd like to visit.

: being preeminently what is indicated

one fine person

She is one tough teacher.

: being the same in kind or quality

both of one species

"Puma" and "cougar" are different names for one animal.

b(1)

: constituting a unified entity of two or more components

The combined elements form one substance.

(2)

: being in agreement or union

am one with you on this

: some sense 1

will see you again one day

: being a certain individual specified by name

one John Doe made a speech

: only sense 2a

the one person she wanted to marry

one

2 of 4

noun

: the first whole number above zero see Table of Numbers

: the number denoting unity

: the first in a set or series

—often used with an attributive noun

day one

: an article of clothing of a size designated one

wears a one

: a single person or thing

has the one but needs the other

: a one-dollar bill

one

3 of 4

pronoun

: a certain indefinitely indicated person or thing

saw one of his friends

: an individual of a vaguely indicated group : anyone at all

one never knows

—used as a third person substitute for a first person pronoun

I'd like to read more but one doesn't have the time.

: a single instance of a specified action

felt like belting him one

John Casey

Using One as a Pronoun: Usage Guide

Sense 2a is usually a sign of a formal style. A formal style excludes the participation of the reader or hearer; thus one is used where a less formal style might address the reader directly.

for the consequences of such choices, one has only oneself to thank

Walker Gibson

This generic one has never been common in informal use in either British or American English, and people who start sentences with one often shift to another pronoun more natural to casual discourse.

when one is learning the river, he is not allowed to do or think about anything else

Mark Twain

Use of one to replace a first-person pronoun—sense 2b—has occasionally been criticized. It is more common in British English than in American.

I'm watching this pretty carefully and I hope that the issue will come up in the Lords and one may be able to speak about it

Donald Coggan

-one

4 of 4

noun suffix

: ketone or related or analogous compound or class of compounds

lactone

quinone

Phrases

at one

: at harmony : in a state of agreement

for one

: as one example

I for one disagree

Example Sentences

Adjective There is one minute left in the game. I have a few one-dollar bills in my purse. She is one year old. Noun one, two, three, four, … I don't have any ones. Can you break a five? I'll be there at one. Pronoun “I'll have an iced tea, please.” “I'll have one, too.” Their dog died, but they plan to get another one. “You should wear the blue one.” “The one with the stripes?” “No, the other one.” I'd like to see the ring next to that one. Which one did you like better? He is the one who called the police. That's one possible answer—but not the only one. I would like to read more, but one doesn't have the time. See More

Recent Examples on the Web

Adjective

Drinkwater didn't make one appearance in a Chelsea shirt last season, whilst Bakayoko spent the season in Italy on loan at AC Milan.

SI.com, 3 Aug. 2019 Decisions made by engineers today, in other words, will determine not how one car drives but how all cars drive.

Johannes Himmelreich, BostonGlobe.com, 30 Mar. 2018 Decisions made by engineers today, in other words, will determine not how one car drives but how all cars drive.

Johannes Himmelreich, Smithsonian, 27 Mar. 2018 Drinkwater didn't make one appearance in a Chelsea shirt last season, whilst Bakayoko spent the season in Italy on loan at AC Milan.

SI.com, 3 Aug. 2019 Decisions made by engineers today, in other words, will determine not how one car drives but how all cars drive.

Johannes Himmelreich, BostonGlobe.com, 30 Mar. 2018 Decisions made by engineers today, in other words, will determine not how one car drives but how all cars drive.

Johannes Himmelreich, BostonGlobe.com, 30 Mar. 2018

Noun

Instead, like so many ugly Christmas sweaters before it, this one, too, will be donated to charity.

Diane Bellcolumnist, San Diego Union-Tribune, 29 Nov. 2022 The Colts and Steelers have bad offenses and are mediocre teams this season, but one comes in the growth process of a young quarterback ascending by the week.

Nate Atkins, The Indianapolis Star, 29 Nov. 2022 This one has jaw-dropping animation and a good theme about how heroism can come from anywhere.

Marisa Lascala, Good Housekeeping, 29 Nov. 2022 From Dan Woike: As far as trades that haven’t happened go, this one has been talked about plenty.

Houston Mitchell, Los Angeles Times, 29 Nov. 2022 Your cat or dog probably won't like us much for suggesting this one, but it's guaranteed to make everyone laugh!

Jennifer Aldrich, Country Living, 29 Nov. 2022 For the second installment of 'Home Alone,' this one with a subhead of 'Lost in New York' follows Kevin McCallister in the big apple trying to escape capture by the wet bandits.

Kristen Adaway, Woman's Day, 29 Nov. 2022 The themes and motifs have shown up in a lot of great collaborations, including this one with Adidas.

John Thompson, Men's Health, 28 Nov. 2022 The Colts come into this one looking to bolster their flagging playoff chances while the Steelers are looking merely to get a win.

Ian Firstenberg, Chicago Tribune, 28 Nov. 2022 See More

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