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unit

1 of 2

noun

1
a
: the first and least natural number : one
b
: a single quantity regarded as a whole in calculation
2
: a determinate quantity (as of length, time, heat, or value) adopted as a standard of measurement
Feet and meters are both units of length.
: such as
a
: an amount of work used in education in calculating student credits
b
: an amount of a biologically active agent (such as a drug or antigen) required to produce a specific result see also international unit
3
a
: a single thing, person, or group that is a constituent of a whole
The family is the basic units of society.
The search party broke up into smaller units.
b
: a part of a military establishment that has a prescribed organization (as of personnel and matériel)
c(1)
: a piece or complex of apparatus serving to perform one particular function
an air conditioning unit
(2)
: a set of similar pieces of furniture that are grouped or attached together
a built-in storage/wall unit
(3)
: an individual item of the products that a company makes or sells
d
: a part of a school course focusing on a central theme
finished the unit on the American Revolution
e
: a local congregation of Jehovah's Witnesses
f
: a small molecule especially when combined in a larger molecule
repeating units of a polymer
g
: an area in a medical facility and especially a hospital that is specially staffed and equipped to provide a particular type of care
an intensive care unit
h
: one of a number of apartment or residences in a building or complex

unit

2 of 2

adjective

: being, relating to, or measuring one unit

Examples of unit in a Sentence

Noun The family is the basic unit of society. The search party broke up into smaller units. Their army unit guarded the border. Feet and meters are units of length. The dollar is the principal unit of American currency.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Cam Johnson staggered instead for a new-look bench unit that coach David Adelman was willing to ride for more than six minutes. Bennett Durando, Denver Post, 25 Nov. 2025 Quinnen Williams’ impact is real After the defense gave up 21 points in a hurry to open the game, the unit saw a huge uptick in improvement as defensive tackle Quinnen Williams started to get home on his pressures. Nick Harris, Fort Worth Star-Telegram, 24 Nov. 2025 The parade features 85-plus units, including 16 marching bands, eight giant cold-air balloons, 12 floats and 46 specialty groups, including five dance teams. Joe Marusak, Charlotte Observer, 24 Nov. 2025 The company plans to produce only 279 Alpha units, according to Humanoids Daily. Atharva Gosavi, Interesting Engineering, 24 Nov. 2025 See All Example Sentences for unit

Word History

Etymology

Noun

back-formation from unity

First Known Use

Noun

1570, in the meaning defined at sense 1a

Adjective

1633, in the meaning defined above

Time Traveler
The first known use of unit was in 1570

Browse Nearby Words

Cite this Entry

“Unit.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unit. Accessed 26 Nov. 2025.

Kids Definition

unit

1 of 2 noun
1
a
: the first and smallest natural number : one
b
: a single quantity regarded as a whole in calculation
2
: a definite quantity (as of length, time, or value) used as a standard of measurement
the dollar is the unit of U.S. money
3
a
: a single thing or person or group that is a part of a whole
b
: a part or arrangement of parts performing one function
a train drawn by two diesel units
c
: a part of a school course with a central theme

unit

2 of 2 adjective
: being, relating to, or measuring one unit of
unit length
unit angle

Medical Definition

unit

noun
1
: an amount of a biologically active agent (as a drug or antigen) required to produce a specific result under strictly controlled conditions
a unit of penicillin
see international unit
2
: a small molecule especially when combined in a larger molecule
repeating units of a polymer
3
: an area in a medical facility and especially a hospital that is specially staffed and equipped to provide a particular type of care
an intensive care unit

More from Merriam-Webster on unit

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