one

[ wuhn ]

/ wʌn /

SEE MORE SYNONYMS FOR one ON THESAURUS.COM

adjective

being or amounting to a single unit or individual or entire thing, item, or object rather than two or more; a single: one woman; one nation; one piece of cake.

being a person, thing, or individual instance or member of a number, kind, group, or category indicated: one member of the party.

existing, acting, or considered as a single unit, entity, or individual.

of the same or having a single kind, nature, or condition: We belong to one team; We are of one resolve.

noting some indefinite day or time in the future: You will see him one day.

a certain (often used in naming a person otherwise unknown or undescribed): One John Smith was chosen.

being a particular, unique, or only individual, item, or unit: I'm looking for the one adviser I can trust.

noting some indefinite day or time in the past: We all had dinner together one evening last week.

of no consequence as to the character, outcome, etc.; the same: It's all one to me whether they go or not.

noun

the first and lowest whole number, being a cardinal number; unity.

a symbol of this number, as 1 or I.

a single person or thing: If only problems would come one at a time!

a die face or a domino face having one pip.

a one-dollar bill: to change a five-dollar bill for five ones.

(initial capital letter) Neoplatonism. the ultimate reality, seen as a central source of being by whose emanations all entities, spiritual and corporeal, have their existence, the corporeal ones containing the fewest of the emanations.

pronoun

a person or thing of a number or kind indicated or understood: one of the Elizabethan poets.

(in certain pronominal combinations) a person unless definitely specified otherwise: every one.

(with a defining clause or other qualifying words) a person or a personified being or agency: the evil one; the one I love.

any person indefinitely; anyone: as good as one would desire.

Chiefly British. (used as a substitute for the pronoun I): Mother had been ailing for many months, and one should have realized it.

a person of the speaker's kind; such as the speaker himself or herself: to press one's own claims.

something or someone of the kind just mentioned: The portraits are fine ones. Your teachers this semester seem to be good ones.

something available or referred to, especially in the immediate area: Here, take one—they're delicious. The bar is open, so have one on me!

Nearby words

ondes martenot, ondine, onding, ondo, ondograph, one, one and all, one and only, one and the same, one another, one by one

Idioms

at one,

in a state of agreement; of one opinion.
united in thought or feeling; attuned: He felt at one with his Creator.

one and all, everyone: They came, one and all, to welcome him home.

one by one, singly and successively: One by one the children married and moved away.

one for the road. road(def 10).

Origin of one

before 900; Middle English oon, Old English ān; cognate with Dutch een, German ein, Gothic ains, Latin ūnus (OL oinos); akin to Greek oínē ace on a die

Can be confused

one wan won (see usage note at the current entry)

Usage note

One as an indefinite pronoun meaning “any person indefinitely, anyone” is more formal than you, which is also used as an indefinite pronoun with the same sense: One (or you ) should avoid misconceptions. One (or you ) can correct this fault in three ways. When the construction requires that the pronoun be repeated, either one or he or he or she is used; he or he or she is the more common in the United States: Wherever one looks, he (or he or she ) finds evidence of pollution. In speech or informal writing, a form of they sometimes occurs: Can one read this without having their emotions stirred?
In constructions of the type one of those who (or that or which ), the antecedent of who is considered to be the plural noun or pronoun, correctly followed by a plural verb: He is one of those people who work for the government. Yet the feeling that one is the antecedent is so strong that a singular verb is commonly found in all types of writing: one of those people who works for the government. When one is preceded by only in such a construction, the singular verb is always used: the only one of her sons who visits her in the hospital.
The substitution of one for I, a typically British use, is usually regarded as an affectation in the United States. See also he¹, they.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for one by one

one

/ (wʌn) /

determiner

single; lone; not two or moreone car
(as pronoun)one is enough for now; one at a time
(in combination)one-eyed; one-legged

distinct from all others; only; uniqueone girl in a million
(as pronoun)one of a kind

a specified (person, item, etc) as distinct from another or others of its kindraise one hand and then the other
(as pronoun)which one is correct?

a certain, indefinite, or unspecified (time); someone day you'll be sorry

informal an emphatic word for a 1, an 1 it was one hell of a fight

a certain (person)one Miss Jones was named

in one or all in one combined; united

all one

all the same
of no consequenceit's all one to me

at one (often foll by with) in a state of agreement or harmony

be made one (of a man and a woman) to become married

many a one many people

neither one thing nor the other indefinite, undecided, or mixed

never a one none

one and all everyone, without exception

one by one one at a time; individually

one or two a few

one way and another on balance

off on one informal exhibiting bad temper; ranting

one with another on average

pronoun

an indefinite person regarded as typical of every personone can't say any more than that

any indefinite person: used as the subject of a sentence to form an alternative grammatical construction to that of the passive voiceone can catch fine trout in this stream

archaic an unspecified personone came to him

noun

the smallest whole number and the first cardinal number; unitySee also number (def. 1)

a numeral (1, I, i, etc) representing this number

informal a joke or story (esp in the one about)

music the numeral 1 used as the lower figure in a time signature to indicate that the beat is measured in semibreves

something representing, represented by, or consisting of one unit

Also called: one o'clock one hour after noon or midnight

a blow or setback (esp in the phrase one in the eye for)

the one (in Neo-Platonic philosophy) the ultimate being

the Holy One or the One above God

the Evil One Satan; the devil

Related forms

Related prefixes: mono-, uni-Related adjective: single

Word Origin for one

Old English ān, related to Old French ān, ēn, Old High German ein, Old Norse einn, Latin unus, Greek oinē ace

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Idioms and Phrases with one by one (1 of 2)

one by one

Also, one at a time. Individually in succession, as in The ducklings jumped into the pond one by one, or One at a time they went into the office. Formerly also put as one and one and one after one, this idiom dates from about a.d. 1000.

Idioms and Phrases with one by one (2 of 2)

one

In addition to the idioms beginning with one

one and all
one and only
one and the same
one another
one by one
one eye on
one fell swoop, in
one foot in the grave, have
one for the books
one for the road
one good turn deserves another
one in a million
one jump ahead
one man's meat is another man's poison
one of a kind
one of these days
one of those days
one on one
one on, that's
one picture is worth a thousand words
one up
one way or another

also see:

all in one piece
all the same (one)
A-1 (A-one)
as one
at one
at one stroke
at one time
at one time or another
back to the drawing board (square one)
each and every (last one)
each other (one another)
fast one
for one, 1
go one better
hang (one) on
harp on (one string)
hole in one
in one ear and out the other
in the same (in one) breath
irons in the fire, more than one
it takes one to know one
just one of those things
look out for (number one)
more than one way to skin a cat
not one iota
number one
on the one hand
(one) picture is worth a thousand words
put all one's eggs in one basket
quick one
seen one, seen them all
six of one, half dozen of the other
that's one on me
tie one on
wear another (more than one) hat
with one arm tied behind one's back
with one voice
words of one syllable

(Note that this listing does not include those idioms where one is a personal pronoun meaning “someone” or “oneself.”)

one

adjective

noun

pronoun

RELATED CONTENT

RELATED WORDS

Nearby words

Idioms

Origin of one

Can be confused

Usage note

British Dictionary definitions for one by one

one

determiner

pronoun

noun

Related forms

Word Origin for one

Idioms and Phrases with one by one (1 of 2)

one by one

Idioms and Phrases with one by one (2 of 2)

one