1 of 4


: 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.
: constituting a unified entity of two or more components
The combined elements form one substance.
: 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


2 of 4


: 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


3 of 4


: 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 oneJohn 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


4 of 4

noun suffix

: ketone or related or analogous compound or class of compounds
at one
: at harmony : in a state of agreement
for one
: as one example
I for one disagree

Examples of one in a Sentence

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
Drinkwater didn't make one appearance in a Chelsea shirt last season, whilst Bakayoko spent the season in Italy on loan at AC Milan., 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,, 30 Mar. 2018
This one has a thicker and higher design than typical rests, and the nonslip bottom keeps it in firmly place. Matthew Parker, Rolling Stone, 19 Nov. 2023 That led to three Denver offensive linemen blocking no one in the middle of the field and allowed pressure from the outside, leading to a strip sack. Jasmine Cui, NBC News, 19 Nov. 2023 The rest of the trial unfolded in a pattern, with the prosecution showing dozens of Facebook posts, photos and videos of Brian’s actions at the Capitol and Brian’s attempts to rationalize each one. Eli Saslow Erin Schaff, New York Times, 19 Nov. 2023 Laura Yarborough Natalie Morales: (pointing to photo of Sarah in her drill team uniform): Tell me about this one. Natalie Morales, CBS News, 18 Nov. 2023 Remember that most slimes (such as this one) are recommended for ages 3 and up. Bridget Shirvell, Parents, 18 Nov. 2023 Another Georgetown shooting, this one in January 2022, left a 27-year-old man from Alexandria, Virginia, dead in the street, according to FOX 5 DC. Michael Ruiz, Fox News, 18 Nov. 2023 Columbia Women's Switchback III Jacket The weather can take a turn at any point when traveling, so having a jacket on hand like this one from Columbia can be a real life-saver. Anna Popp, Travel + Leisure, 18 Nov. 2023 This one comes with 12 festive and interactive toys, including some balls, mice, a wand, and, of course, a plush Santa. Jessie Quinn, Peoplemag, 18 Nov. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'one.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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


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


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


13th century, in the meaning defined at sense 1

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