core

UK: /ˈkɔː/

US: /kɔr/

US: 'core': (kôr, kōr); 'Core': (kôr′ē, kōr′ē)

Inflections of 'core' (v): (⇒ conjugate)

cores

v 3rd person singular

coring

v pres p

cored

v past

cored

v past p

WordReference Random House Learner's Dictionary of American English © 2025

core¹ /kɔr/   n., v., cored, cor•ing. 
n. [countable]

1. Botany the central part of a fleshy fruit, containing the seeds:
   Remove the cores from the apples.
2. the central part of the earth:
   [singular] the pressure at the earth's core.
3. the most important or essential part of anything:
   the core of the new curriculum for business majors.
4. Physics the region in a nuclear reactor that contains the radioactive material used to produce energy.

v. [~ + object]

5. to remove the core of (fruit):
   Core the apples.

Idioms

6. to the core, [uncountable] completely;
   thoroughly:
   The villain was rotten to the core.

core•less, adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

core¹  (kôr, kōr), n., v., cored, cor•ing. 
n. 

1. Botany the central part of a fleshy fruit, containing the seeds.
2. the central, innermost, or most essential part of anything.
3. Electricity Also called magnetic core. the piece of iron, bundle of iron wires, or other ferrous material forming the central or inner portion in an electromagnet, induction coil, transformer, or the like. See diag. under electromagnet. 
4. Geology, Mining (in mining, geology, etc.) a cylindrical sample of earth, mineral, or rock extracted from the ground by means of a corer so that the strata are undisturbed in the sample.
5. Botany the inside wood of a tree.
6. Anthropology, Archaeology a lump of stone, as flint, from which prehistoric humans struck flakes in order to make tools. Cf. flake tool.
7. Building [Carpentry.]
   • a thickness of wood forming a base for a veneer.
   • a wooden construction, as in a door, forming a backing for veneers.
8. Civil Engineering, Building [Engin.] kern².
9. Metallurgy
   • a thickness of base metal beneath a cladding.
   • the softer interior of a piece of casehardened metal.
   • a specially formed refractory object inserted into a mold to produce cavities or depressions in the casting that cannot be readily formed on the pattern.
10. Geology the central portion of the earth, having a radius of about 2100 mi. (3379 km) and believed to be composed mainly of iron and nickel in a molten state. Cf. crust (def. 6), mantle (def. 3).
11. Physics the region in a reactor that contains its fissionable material.
12. Computing Also called magnetic core. a small ring or loop of ferromagnetic material with two states of polarization that can be changed by changing the direction of the current applied in wires wound around the ring, used to store one bit of information or to perform switching or logical functions.
13. Textiles [Ropemaking.] heart (def. 16).
14. [Phonet.] the final segment of a syllable beginning with the vowel and including any following consonants;
    the nucleus plus the coda. Cf. onset (def. 3).

v.t. 

15. to remove the core of (fruit).
16. to cut from the central part.
17. to remove (a cylindrical sample) from the interior, as of the earth or a tree trunk:
    to core the ocean bottom.
18. to form a cavity in (a molded object) by placing a core, as of sand, in the mold before pouring.

• Latin corpus
• Old French cors body
• 1275–1325; 1945–50 for def. 11; Middle English; origin, originally uncertain; perh.

core′less, adj. 
Synonyms

• 2. essence, heart, gist, center.

core²  (kôr, kōr), n. [Chiefly Scot.]

1. Scottish Terms a small company or group of people, esp. a gang of miners or a small corps of workers.

• Middle English chor(e) dance, company of dancers or singers. See chorus 1150–1200

Co•re  (kôr′ē, kōr′ē), n. 

1. Bible Korah.
2. Mythology [Class. Myth.] Kore.

CORE  (kôr, kōr), n. 

1. Congress of Racial Equality.

Also, C.O.R.E. 

Collins Concise English Dictionary © HarperCollins Publishers::

core / kɔː/ noun

1. the central part of certain fleshy fruits, such as the apple or pear, consisting of the seeds and supporting parts
2. the central, innermost, or most essential part of something: the core of the argument
3. a piece of magnetic material, such as soft iron, placed inside the windings of an electromagnet or transformer to intensify and direct the magnetic field
4. the central part of the earth, beneath the mantle, consisting mainly of iron and nickel, which has an inner solid part surrounded by an outer liquid part
5. a cylindrical sample of rock, soil, etc, obtained by the use of a hollow drill
6. shaped body of material (in metal casting usually of sand) supported inside a mould to form a cavity of predetermined shape in the finished casting
7. the region of a nuclear reactor in which the reaction takes place
8. one of several processing units working in parallel in a computer
9. a ferrite ring formerly used in a computer memory to store one bit of information
10. (as modifier): core memory
11. a lump of stone or flint from which flakes or blades have been removed
12. the nucleus together with all complete electron shells of an atom

verb

1. (transitive) to remove the core from (fruit)

Etymology: 14th Century: of uncertain origin