unit

1 of 2

noun

ˈyü-nət 

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 unit 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

Noun

But planning has centered on the possible deployment of forces from the secretive Joint Special Operations Command, the elite military unit often tasked with the most sensitive counter-proliferation missions, two of the sources told CBS News. —Jennifer Jacobs, CBS News, 21 Mar. 2026

The 11th Marine Expeditionary Unit (MEU) is headed to the Middle East on an accelerated timeline, a defense official told USA TODAY, bringing the number of Marines joining the Iran war to nearly 5,000 after another of the units deployed last week. —Cybele Mayes-Osterman, USA Today, 21 Mar. 2026

The researchers aim to cut costs by simplifying the system and partnering with manufacturers to produce the control unit at scale. —Neetika Walter, Interesting Engineering, 21 Mar. 2026

Meanwhile, Century 21 Judge Fite Property Management manages over 2,000 units following the acquisition, Fite said. —Nick Wooten, Dallas Morning News, 20 Mar. 2026

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

Phrases Containing unit

• absolute unit
• astronomical unit
• atomic mass unit
• base unit
• British thermal unit
• canine unit
• central processing unit
• critical care unit
• electromagnetic unit
• imaginary unit
• intensive care unit
• international bitterness unit
• international unit
• inter-unit
• kitchen unit
• living unit
• monetary unit
• motor unit
• sub-unit
• unit cell
• unit character
• unit circle
• unit membrane
• unit rule
• unit train
• unit trust
• waste disposal unit

Kids Definition

unit

1 of 2 noun

ˈyü-nət 

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

ˈyü-nət 

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