core / kôr/ • n. 1. the tough central part of various fruits, containing the seeds: an apple core.2. the central or most important part of something, in particular: ∎  [often as adj.] the part of something that is central to its existence or character: managers can concentrate on their core activities | the plan has the interests of children at its core. ∎  an important or unchanging group of people forming the central part of a larger body. ∎  the dense central region of a planet, esp. the nickel–iron inner part of the earth. ∎  the central part of a nuclear reactor, which contains the fissile material. ∎  a tiny ring of magnetic material used in a computer memory to store one bit of data, now superseded by semiconductor memories. ∎  the inner strand of an electrical cable or rope. ∎  a piece of soft iron forming the center of an electromagnet or an induction coil. ∎  an internal mold filling a space to be left hollow in a casting. ∎  a cylindrical sample of rock, ice, or other material obtained by boring with a hollow drill. ∎  Archaeol. a piece of flint from which flakes or blades have been removed.• v. [tr.] remove the tough central part and seeds from (a fruit).DERIVATIVES: cor·er n.

core
1. The central zone or unit of the Earth. It is composed of iron, with a lighter element, probably sulphur, and accounts for 16% of the Earth's volume and 32% of its mass. The core is separated into inner and outer units. The inner core is a solid with a radius of about 1220 km and the outer core, which does not permit the passage of shear waves (S-waves), is liquid. Other planets have mass distributions that suggest they possess cores, e.g. Mars, Venus, and Mercury. The Moon may have a small core. Saturn has magnetic fields interpreted to indicate a metallic core, probably of liquid hydrogen.

2. A rock specimen obtained by drilling.

core Central area of the Earth from a depth of 2885km (1790mi). It accounts for 16% of the Earth's volume and 31% of its mass. Information about the core is obtained from the measurement of seismic waves. These indicate that the outer part of the core is liquid, because shear (S) waves will not travel through it, whereas the inner core from 5150km (3200mi) to the centre of the Earth is interpreted as solid because seismic velocities are lower. It is believed that the change from liquid to solid core occurs because of immense pressure conditions. The core is thought to be composed of iron-nickel alloy (90% iron, 10% nickel). Temperature estimates for the core vary from 4000 to 7000°C (7200–12,600°F). Convection in the iron liquid outer core is thought to be responsible for producing the Earth's magnetic field.

CORE A method with supporting tools for capturing, structuring, and expressing system and software requirements. It was originally devised by British Aerospace (BAe) in 1979 and later extended by BAe and Systems Designers in the UK. CORE supports the different roles and viewpoints of user, customer, and analyst, and provides techniques to ensure completeness, consistency, and lack of ambiguity by cross-referencing between viewpoints. The informal CORE notation provides a series of diagramming techniques and associated text descriptions.

CORE / kôr/ • abbr. Congress of Racial Equality.