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

Gould spent the next two days in a coma in the intensive care unit, on a ventilator. —Kerry Breen, CBS News, 18 Apr. 2026

The unit also added transfer Jailen Duffie and freshmen Elijah Keys and Amarion Queen. —Matt Murschel, The Orlando Sentinel, 18 Apr. 2026

Where is the family unit that existed before? —Jean Garnett, New Yorker, 18 Apr. 2026

The unit is built to move fast, turning prototypes into operational assets, developing doctrine, and pushing autonomous systems into real-world missions, marking Australia’s transition from trials to frontline capability, reported Army Recognition. —Prabhat Ranjan Mishra, Interesting Engineering, 17 Apr. 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