core (Noun) — An organization founded by James Leonard Farmer in 1942 to work for racial equality.
core (Noun) — A small group of indispensable persons or things. ex. "five periodicals make up the core of their publishing program"
core (Noun) — The centre of an object. ex. "the ball has a titanium core"
core (Noun) — The central part of the Earth.
core (Noun) — The choicest or most essential or most vital part of some idea or experience. ex. "the core of the prosecutor's argument"
core (Noun) — A cylindrical sample of soil or rock obtained with a hollow drill.
core (Noun) — The central meaning or theme of a speech or literary work.
core (Noun) — (computing) a tiny ferrite toroid formerly used in a random access memory to store one bit of data; now superseded by semiconductor memories. ex. "each core has three wires passing through it, providing the means to select and detect the contents of each bit"
core (Noun) — The chamber of a nuclear reactor containing the fissile material where the reaction takes place.
core (Noun) — A bar of magnetic material (as soft iron) that passes through a coil and serves to increase the inductance of the coil.
core (Verb) — Remove the core or centre from. ex. "core an apple"