Synonyms for core

a small group of indispensable persons or things (noun)

• nucleus

the choicest or most essential or most vital part of some idea or experience (noun)

• kernel
• substance
• center
• centre
• essence
• gist
• heart
• inwardness
• marrow
• meat
• nub
• pith
• sum
• nitty-gritty

an organization founded by James Leonard Farmer in 1942 to work for racial equality (noun)

the central meaning or theme of a speech or literary work (noun)

• effect
• burden

(computer science) a tiny ferrite toroid formerly used in a random access memory to store one bit of data (noun)