core · noun /kɔːr/
core (IMPORTANT PART)
C2 no plural the most important part of a system or principle
Dictionary examples:
core values
Better health care was at the core of the senator's campaign.
Learner example:
The aim of this paper is to respond to a call for proposals [from] a TV company which is planning to launch a program called "Making the World a Better Place" and to select the group of people which represents the core idea of this program. (Certificate of Proficiency in English; C2; Czech)
core (FRUIT)
C2 C the hard, central part of certain fruits, such as apples, which contains the seeds
Dictionary example:
Peel the apples and remove the cores.
Learner example:
So there it was, hidden in nature, occasionally trampled by a stray dog with no other companion than old cans and apple cores. (Certificate of Proficiency in English; C2; Spanish)