Merriam-Webster Collegiate Dictionary - core

 abbreviation Congress of Racial Equality CORE  I. noun  Usage: often attributive  Etymology: Middle English  Date: 14th century  1. a central and often foundational part usually distinct from the enveloping part by a difference in nature the ~ of the city: as  a. the usually inedible central part of some fruits (as a pineapple); especially the papery or leathery carpels composing the ripened ovary in a pome fruit (as an apple)  b. the portion of a foundry mold that shapes the interior of a hollow casting  c. a vertical space (as for elevator shafts, stairways, or plumbing apparatus) in a multistory building  d.  (1) a mass of iron serving to concentrate and intensify the magnetic field resulting from a current in a surrounding coil  (2) a tiny doughnut-shaped piece of magnetic material (as ferrite) used in computer memories  (3) a computer memory consisting of an array of ~s strung on fine wires; broadly the internal memory of a computer  e. the central part of a celestial body (as the earth or sun) usually having different physical properties from the surrounding parts  f. a nodule of stone (as flint or obsidian) from which flakes have been struck for making implements  g. the conducting wire with its insulation in an electric cable  h. 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 ~ curriculum  i. the place in a nuclear reactor where fission occurs  2.  a. a basic, essential, or enduring part (as of an individual, a class, or an entity) the staff had a ~ of experts the ~ of her beliefs  b. the essential meaning ; gist the ~ of the argument  c. the inmost or most intimate part honest to the ~  3. a part (as a thin cylinder of material) removed from the interior of a mass especially to determine composition  II. transitive verb  (~d; coring)  Date: 15th century to remove a ~ from ~ an apple  • ~r noun  III. noun  Etymology: perhaps alteration of Middle English chore chorus, company, perhaps from Latin chorus  Date: 1622 chiefly Scottish a group of people