one

1 of 4

adjective

1
: being a single unit or thing
one day at a time
She is one year old.
2
a
: being one in particular
early one morning
The Grand Canyon is one place I'd like to visit.
b
: being preeminently what is indicated
one fine person
She is one tough teacher.
3
a
: 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
4
a
: some sense 1
will see you again one day
b
: being a certain individual specified by name
one John Doe made a speech
5
: only sense 2a
the one person she wanted to marry

one

2 of 4

noun

1
: the first whole number above zero see Table of Numbers
2
: the number denoting unity
3
a
: the first in a set or series
often used with an attributive noun
day one
b
: an article of clothing of a size designated one
wears a one
4
: a single person or thing
has the one but needs the other
5
: a one-dollar bill

one

3 of 4

pronoun

1
: a certain indefinitely indicated person or thing
saw one of his friends
2
a
: an individual of a vaguely indicated group : anyone at all
one never knows
b
used as a third person substitute for a first person pronoun
I'd like to read more but one doesn't have the time.
3
: 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 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
That means this one is sturdy enough to accommodate virtually any workout regimen. Mike Richard, Men's Health, 17 Nov. 2022 This one is a 1996 model with about 103,000 kilometers (64,000 miles) on the odometer. Brendan Mcaleer, Car and Driver, 17 Nov. 2022 No one was there when officers arrived, but the suspect, who is known to police was found hiding in the brush near a playground by a K-9 officer. Joan Rusek, cleveland, 17 Nov. 2022 This one is a must-have for the Black-woman writer, author, or creative in your life. Ebony Flake, Essence, 16 Nov. 2022 Depp sounds resigned to it, which is maybe all one can be in her situation. Véronique Hyland, ELLE, 16 Nov. 2022 This one is less so a prediction, but more the show inspiring a real-life event. Mike Bloom, The Hollywood Reporter, 16 Nov. 2022 In line with other Chanel products, this one is lightly fragranced, which could be a pro for some and a con for others depending on scent preference. Madison Yauger, Peoplemag, 15 Nov. 2022 This one with a waffle design made out of 100% organic cotton is both breathable and absorbent. Ysolt Usigan, Woman's Day, 15 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.

Word History

Etymology

Adjective, Noun, and Pronoun

Middle English on, an, from Old English ān; akin to Old High German ein one, Latin unus (Old Latin oinos), Sanskrit eka

Noun suffix

International Scientific Vocabulary, alteration of -ene

First Known Use

Adjective

before the 12th century, in the meaning defined at sense 1

Noun

before the 12th century, in the meaning defined at sense 1

Pronoun

13th century, in the meaning defined at sense 1

Time Traveler
The first known use of one was before the 12th century

Dictionary Entries Near one

Cite this Entry

“One.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/one. Accessed 28 Nov. 2022.

Kids Definition

one 1 of 3

adjective

ˈwən How to pronounce one (audio)
ˌwən
1
: being a single unit or thing see number
2
: being a certain unit or thing
early one morning
3
a
: being the same in kind or quality
members of one class
b
: not divided
4
: not definitely fixed or placed
will see you again one day
5
: only entry 1 sense 2a
the one person they wanted to see

one

2 of 3

noun

1
: the number indicating a single unit
2
: the first in a set or series
3
: a single person or thing
has the one, but needs the other
4
: a one-dollar bill

one

3 of 3

pronoun

1
: a single member or individual
saw one of your friends
2
: any person
one never knows

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