CORE definition

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

(2) The chamber of a nuclear reactor containing the fissile material where the reaction takes place

(3) 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"

(4) The central meaning or theme of a speech or literary work

(5) A small group of indispensable persons or things

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

(6) An organization founded by James Leonard Farmer in 1942 to work for racial equality

(7) The center of an object

"The ball has a titanium core"

(8) The central part of the Earth

(9) A cylindrical sample of soil or rock obtained with a hollow drill

(10) Remove the core or center from

"Core an apple"