core

a small group of indispensable persons or things; "five periodicals make up the core of their publishing program"

the center of an object; "the ball has a titanium core"

the central part of the Earth

the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"

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

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

the central meaning or theme of a speech or literary work

(computer science) a tiny ferrite toroid formerly used in a random access memory to store one bit of data; now superseded by semiconductor memories; "each core has three wires passing through it, providing the means to select and detect the contents of each bit"

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

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

remove the core or center from; "core an apple"