core

noun

1. The central part of a fruit, containing the kernels or seeds.
2. The heart or inner part of a physical thing.
3. The anatomical core, muscles which bridge abdomen and thorax.
4. The center or inner part of a space or area.
5. The most important part of a thing or aggregate of things wherever located and whether of any determinate location at all; the essence.
6. The main and most diverse monophyletic group within a clade or taxonomic group.
7. The set of feasible allocations that cannot be improved upon by a subset (a coalition) of the economy's agents.
8. A thematic aesthetic; objects related to a specific topic
9. The portion of a mold that creates a cavity or impression within the part (casting or molded part) or that makes a hole in or through the part.
10. An individual computer processor, in the sense when several processors (called cores or CPU cores) are plugged together in one single integrated circuit to work as one (called a multi-core processor).
11. The material between surface materials in a structured composite sandwich material.
12. The inner part of a nuclear reactor, in which the nuclear reaction takes place.
13. The central fissile portion of a fission weapon.
14. A piece of ferromagnetic material (e.g., soft iron), inside the windings of an electromagnet, that channels the magnetic field.
15. A hollow cylindrical piece of cardboard around which a web of paper or plastic is wound.
16. A tiny sample of organic material obtained by means of a fine-needle biopsy.
17. The bony process which forms the central axis of the horns in many animals.
18. A disorder of sheep caused by worms in the liver.
19. The central part of a protein's structure, consisting mostly of hydrophobic amino acids.
20. A cylindrical sample of rock or other materials obtained by core drilling.