noun (1), often attributive
\ ˈkȯr How to pronounce core (audio) \
plural cores

Definition of core

 (Entry 1 of 4)

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
2a : 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


cored; coring

Definition of core (Entry 2 of 4)

transitive verb

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


noun (2)

Definition of core (Entry 3 of 4)

chiefly Scotland
: a group of people
\ ˈkȯr How to pronounce CORE (audio) \

Definition of CORE (Entry 4 of 4)

Congress of Racial Equality

Other Words from core


corer noun

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.

First Known Use of core

Noun (1)

14th century, in the meaning defined at sense 1


15th century, in the meaning defined above

Noun (2)

1622, in the meaning defined above

History and Etymology for core

Noun (1)

Middle English, of obscure origin


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

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Time Traveler for core

Time Traveler

The first known use of core was in the 14th century

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Cite this Entry

“Core.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2021.

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More Definitions for core



English Language Learners Definition of core

: to remove a core from (a fruit)


\ ˈkȯr How to pronounce core (audio) \

Kids Definition of core

 (Entry 1 of 2)

1 : the usually inedible central part of some fruits (as a pineapple or pear)
2 : the central part of a heavenly body (as the earth or sun)
3 : the central or most important part of something the core of a golf ball the core of a problem


cored; coring

Kids Definition of core (Entry 2 of 2)

: to remove the core from core an apple


\ ˈkō(ə)r, ˈkȯ(ə)r How to pronounce core (audio) \

Medical Definition of core

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

More from Merriam-Webster on core

Nglish: Translation of core for Spanish Speakers

Britannica English: Translation of core for Arabic Speakers


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