Definition of "Core" :

noun: a bar of magnetic material (as soft iron) that passes through a coil and serves to increase the inductance of the coil

noun: the chamber of a nuclear reactor containing the fissile material where the reaction takes place

noun: (computer science) a tiny ferrite toroid formerly used in a random access memory to store one bit of data; now superseded by semiconductor memories

"Each core has three wires passing through it, providing the means to select and detect the contents of each bit."

noun: the choicest or most essential or most vital part of some idea or experience

noun: the central meaning or theme of a speech or literary work

noun: a small group of indispensable persons or things

"Five periodicals make up the core of their publishing program."

noun: an organization founded by James Leonard Farmer in 1942 to work for racial equality

noun: the center of an object

"The ball has a titanium core."

noun: the central part of the Earth

noun: a cylindrical sample of soil or rock obtained with a hollow drill

verb: remove the core or center from

"Core an apple."