Core likely comes from Old French 'cor' (body), from Latin 'corpus,' originally referring to the central body of a fruit.
The central or most important part of something; the tough central part of various fruits containing the seeds.
From Old French 'cor' or 'cors' (body, heart), from Latin 'corpus' (body), from PIE *kwerp- (body, form, shape). The PIE root gives Sanskrit 'krp-' (form, beauty) and Avestan 'kərəfš' (body). Latin 'corpus' evolved through Old French with shortening of the vowel. The fruit sense — the central seed-bearing mass — appeared in English c.1400, with the abstract