core(1) the tough central part of various fruits, containing the seeds an apple core 2) the part of something that is central to its existence or character the plan has the interests of children at its core | [as modifier] managers can concentrate on their core activities ¦ an important or unchanging group of people forming the central part of a larger body 3) the dense central region of a planet, especially the nickel-iron inner part of the earth ¦ the central part of a nuclear reactor, which contains the fissile material. NOED Alexander Demidov)
