core
UK: kɔː | US: kɔːr
n. the central or most important part of something
n. the tough central part of various fruits, containing the seeds
adj. fundamental or essential
The word "core" traces back to the Latin cor, meaning "heart," which metaphorically extended to signify the central or vital part of anything. Borrowed into Old French as cor, it entered Middle English with the same meaning. Over time, its usage expanded to describe the central part of fruits (e.g., apple core) and abstract concepts (e.g., core values), retaining the idea of centrality and importance.
The core of the argument was about fairness.
She removed the core from the apple before slicing it.
The Earth's core is composed of iron and nickel.
His speech touched on the core issues facing society.
The team focused on strengthening the core principles of the project.