core

Etymology 1

From Middle English core, kore, coor (“apple-core, pith”), of uncertain origin. Possibly of native English origin (compare Old English corn (“seed", also "grain”), or perhaps from Old French cuer (“heart”), from Latin cor (“heart”); or from Old French cors (“body”), from Latin corpus (“body”). Compare also Middle English colk, coke, coll (“the heart or centre of an apple or onion, core”), Dutch kern (“core”), German Kern (“core”). See also heart, corpse.

noun

1. In general usage, an essential part of a thing surrounded by other essential things.
   1. The central part of a fruit, containing the kernels or seeds.
      the core of an apple or quince
   2. The heart or inner part of a physical thing.
      Reindeer are well suited to the taiga’s frigid winters. They can maintain a thermogradient between body core and the environment of up to 100 degrees, in part because of insulation provided by their fur, and in part because of counter-current vascular heat exchange systems in their legs and nasal passages. 2013-03, Nancy Langston, “Mining the Boreal North”, in American Scientist, volume 101, number 2, page 98
   3. The anatomical core, muscles which bridge abdomen and thorax.
   4. The center or inner part of a space or area.
2. The most important part of a thing or aggregate of things wherever located and whether of any determinate location at all; the essence.
   1. A technical term for classification of things denoting those parts of a category that are most easily or most likely understood as within it.
      1. (botany) Used to designate the main and most diverse monophyletic group within a clade or taxonomic group.
      2. (game theory) The set of feasible allocations that cannot be improved upon by a subset (a coalition) of the economy's agents.
   2. (art) A thematic aesthetic; objects related to a specific topic
      Photographs of cottagecore focuses on countrysides or forests.
3. particular parts of technical instruments or machines essential in function:
   1. (engineering) The portion of a mold that creates an internal cavity within a casting or that makes a hole in or through a casting.
   2. (computing, informal, historical) Ellipsis of core memory.; magnetic data storage.
   3. (computer hardware) An individual computer processor, in the sense when several processors (called cores or CPU cores) are plugged together in one single integrated circuit to work as one (called a multi-core processor).
      I wanted to play a particular computer game, which required I buy a new computer, so while the game said it needed at least a dual-core processor, I wanted my computer to be a bit ahead of the curve, so I bought a quad-core.
   4. (engineering) The material between surface materials in a structured composite sandwich material.
      a floor panel with a Nomex honeycomb core
   5. (engineering, nuclear physics) The inner part of a nuclear reactor, in which the nuclear reaction takes place.
   6. (military) The central fissile portion of a fission weapon.
      In a hollow-core design, neutrons escape from the core more readily, allowing more fissile material to be used (and thus allowing for a greater yield) while still keeping the core subcritical prior to detonation.
   7. A piece of ferromagnetic material (e.g., soft iron), inside the windings of an electromagnet, that channels the magnetic field.
   8. (printing) A hollow cylindrical piece of cardboard around which a web of paper or plastic is wound.
4. Hence particular parts of a subject studied or examined by technical operations, likened by position and practical or structural robustness to kernels, cores in the most vulgar sense above.
   1. (medicine) A tiny sample of organic material obtained by means of a fine-needle biopsy.
   2. The bony process which forms the central axis of the horns in many animals.
   3. A disorder of sheep caused by worms in the liver.
      [the skin of the sheep] is clear from cores and jogs under the jaws. 1750, William Ellis, Modern Husbandry or Practice of Farming
   4. (biochemistry) The central part of a protein's structure, consisting mostly of hydrophobic amino acids.
   5. A cylindrical sample of rock or other materials obtained by core drilling.
   6. (physics) An atomic nucleus plus inner electrons (i.e., an atom, except for its valence electrons).

adj

1. Forming the most important or essential part.
   Privately held businesses may hold assets or have charges to their financial statements which are not core to their main business activity. 2009, Greg Hayes, A Practical Guide to Business Valuations for SMEs, page 68
   Private-equity nabobs bristle at being dubbed mere financiers. Piling debt onto companies’ balance-sheets is only a small part of what leveraged buy-outs are about, they insist. Improving the workings of the businesses they take over is just as core to their calling, if not more so. Much of their pleading is public-relations bluster. 2013-06-22, “Engineers of a different kind”, in The Economist, volume 407, number 8841, page 70
   These lists cover important vocabulary from eight core subjects that students need to master during secondary education: Biology, Chemistry, Economics, English, Geology, History, Mathematics, and Physics. 2018, Clarence Green, James Lambert, “Advancing disciplinary literacy through English for academic purposes: Discipline-specific wordlists, collocations and word families for eight secondary subjects”, in Journal of English for Academic Purposes, volume 35, →DOI, page 106
2. (board sports) Deeply and authentically involved in the culture surrounding the sport.
   Our interest is not in core skaters such as young males and pro skaters but the voices of those on the periphery of the subculture. 2015, Kara-Jane Lombard, Skateboarding: Subcultures, Sites and Shifts, page 45
   We had a segmentation strategy, where the small, independent core skate shops — the three hundred boutiques around the country who really created us — had a certain product line that was exclusive to them. […] We said to the core shops, you don't have to compete with the malls. 2022, Malcolm Gladwell, The Tipping Point: How Little Things Can Make a Big Difference
   […] which provoked resistance among the 'core' snowboarders. 2023, Mari Kristin Sisjord, Women in Snowboarding

verb

1. To remove the core of an apple or other fruit.
2. To cut or drill through the core of (something).
   But the other thing to take into account is, when you look at the Katahdin and the Polyphemus, they both have their boiler plants pretty much amidships or slightly forward of amidships, which means that, in the event of a heat-lance strike on the boiler room, not only is that gonna core through the ship right at the center of mass, which is obviously bad for its continued structural stability, but the boilers going up is gonna incinerate pretty much anybody on the bridge, which is gonna leave it completely out of control, and is probably gonna break the ship clean in half right there and then, none of which really speaks to the ship's being able to continue onwards with enough momentum to take down a Martian tripod. 1 April 2020, Drachinifel, 6:52 from the start, in HMS Thunderchild - A bad day to be a Tripod, archived from the original on 2022-09-24
3. To extract a sample with a drill.

Etymology 2

See corps

noun

1. (obsolete) A body of individuals; an assemblage.

Etymology 3

See chore.

noun

1. A miner's underground working time or shift.

Etymology 4

From Hebrew כֹּר.

noun

1. (historical units of measure) Alternative form of cor: a former Hebrew and Phoenician unit of volume.

Etymology 5

Possibly an acronym for cash on return.

noun

1. (automotive, machinery, aviation, marine) A deposit paid by the purchaser of a rebuilt part, to be refunded on return of a used, rebuildable part, or the returned rebuildable part itself.

Etymology 6

From -core, ultimately from Etymology 1.

noun

1. (neologism) An aesthetic ending in the suffix -core, such as cottagecore, normcore, etc.
   The rise of micro-cores coincides with the rise of hyper-specific internet aesthetics. There's even an Aesthetics Wiki that chronicles all the possible cores online, including, but not limited to, bubblegumbitchcore, cottagecore, and fairycore. 27 July 2022, Sarah Spellings, “Core Is the New Chic”, in Vogue, New York, N.Y.: Condé Nast Publications, →ISSN, →OCLC, archived from the original on 2023-05-15
   It's more than okay to let a microtrend be just that. Naming it as a "core" turns the clothing into a social media movement, and more often than not, the title is an overcomplication for rather basic color choices or fabric selections. 23 December 2022, Dylan Kelly, “Can 2023 Be the Year of "Nothingcore"?”, in Hypebeast, archived from the original on 2023-06-01
   The aesthetic makes a convincing case for finding joy in fashion and experimenting with personal style rather than chasing every new 'core' that comes along. It encourages real excitement about getting creative with the clothes you already have in your wardrobe and therein lies the thrill of it. 2 March 2023, Sophie Lou Wilson, “Cluttercore: Why The 2010s Blogger Aesthetic Is Back In Style”, in Refinery29, archived from the original on 2023-07-06