core

1 of 4

noun (1)

ˈkȯr 

plural cores

often attributive

1

: a central and often foundational part usually distinct from the enveloping part by a difference in nature

the core of the city

: such as

a

: the usually inedible central part of some fruits (such as a pineapple)

especially : the papery or leathery carpels composing the ripened ovary in a pome fruit (such as an apple)

b

: the muscles of the mid-region of the torso

Your core is composed of the muscles that stabilize and move your pelvis, lower back, hips, and trunk.

—Adele Jackson-Gibson

core muscles/strength

core exercises

c

: the place in a nuclear reactor where fission (see fission entry 1 sense 3) occurs

d

: an arrangement of a course of studies that combines under basic topics material from subjects conventionally separated and aims to provide a common background for all students

core curriculum

e

: the portion of a foundry mold that shapes the interior of a hollow casting

f

: a vertical space (as for elevator shafts, stairways, or plumbing apparatus) in a multistory building

g(1)

: a computer memory consisting of an array of cores strung on fine wires

broadly : the internal memory of a computer

(2)

: a tiny doughnut-shaped piece of magnetic material (such as ferrite) used in computer memories

(3)

: a mass of iron serving to concentrate and intensify the magnetic field resulting from a current in a surrounding coil

h

: the central part of a celestial body (such as the earth or sun) usually having different physical properties from the surrounding parts

i

: a nodule of stone (such as flint or obsidian) from which flakes have been struck for making implements

j

: the conducting wire with its insulation in an electric cable

2

a

: a basic, essential, or enduring part (as of an individual, a class, or an entity)

the staff had a core of experts

the core of her beliefs

b

: the essential meaning : gist

the core of the argument

c

: the inmost or most intimate part

honest to the core

3

: a part (such as a thin cylinder of material) removed from the interior of a mass especially to determine composition

core

2 of 4

verb

cored; coring

transitive verb

: to remove a core (see core entry 1 sense 1a) from

core an apple

corer noun

core

3 of 4

noun (2)

chiefly Scotland

: a group of people

CORE

4 of 4

abbreviation

ˈkȯr 

Congress of Racial Equality

Did you know?

Distinguishing Between Core and Corps and Corpse and Corp

These words are frequently confused despite their very different applications. Core and corps both rhyme with more. Core can be a noun, verb, or adjective, but is most often used as a noun to refer to the central or most important part of something (“the core of the issue,” “the Earth’s core”) or to the usually inedible central part of a fruit (“an apple core”). Corps has several meanings, all of which refer to some kind of group: “the Marine Corps,” “the press corps.” Its plural form is also spelled corps (“two corps of reporters”) but is pronounced just as cores is. Unlike in corps, The “p” in corpse and corp is pronounced. Corpse refers to a dead body, and especially to the dead body of a human. Corp is an abbreviation for “corporation” and “corporal.” Corp, corps, and corpse all trace back to the Latin word corpus, meaning “body.” The origin of core is obscure.

Synonyms

Noun (1)

• heart
• soul

Examples of core in a Sentence

Noun (1)

in my very core I knew that an injustice was being committed

the capitol building is the core of the political life of the state

at last, we come to the core of the issue that has been dividing us

a starfish can even survive the division of its core into two parts; both halves then regenerate

the mountain rises from ground that is almost precisely at the island's core

Recent Examples on the Web

Noun

Their back-and-forth makes up the core of the film, as twists, turns and discoveries gradually unfold. —William Earl, Variety, 25 Oct. 2025

Intel — The chip stock surged more than 7% in premarket trading after the company reported better-than-expected revenue as demand for its core x86 processors for PCs recovered. —Yun Li, CNBC, 24 Oct. 2025

Verb

Peel and core the apples, then slice into thin wedges. —Kathryn Gregory, Louisville Courier Journal, 21 Oct. 2025

The seafloor within the rings around the barrels had hardened like concrete, preventing them from collecting samples with a coring device that would be inserted into the seafloor. —Maura Fox, San Diego Union-Tribune, 11 Sep. 2025

Word History

Etymology

Noun (1)

Middle English, of obscure origin

Verb

Middle English coren, derivative of core core entry 1

Noun (2)

perhaps by respelling of Middle English chore "chorus, company," borrowed from Latin chorus — more at chorus entry 1

First Known Use

Noun (1)

14th century, in the meaning defined at sense 1

Verb

15th century, in the meaning defined above

Noun (2)

1622, in the meaning defined above

Phrases Containing core

• core city
• core competencies
• core inflation
• hard core
• rotten to the core
• shaken to the core
• soft-core
• to the core

Rhymes for core

• boar
• boer
• bore
• chore
• cor
• corps
• crore
• door
• drawer
• floor
• flor
• for

Kids Definition

core

1 of 2 noun

ˈkō(ə)r 

ˈkȯ(ə)r

1

: a central or most important part

2

: the usually inedible central part of some fruits (as a pineapple or apple)

3

: a part removed from the interior of a mass especially to find out the interior composition or a hidden condition

took a core of rock

4

a

: a mass of iron used to concentrate and strengthen the magnetic field resulting from a current in a surrounding coil

b

: the memory of a computer

5

: the central part of the earth having different properties from those of the surrounding parts

also : the central part of a heavenly body

6

: an arrangement of studies that brings together material from subjects that are usually taught separately

7

: the place in a nuclear reactor where fission takes place

core

2 of 2 verb

cored; coring

: to remove a core from

core an apple

corer noun

Medical Definition

core

noun

ˈkō(ə)r, ˈkȯ(ə)r 

: the central part of a body, mass, or part