| nucleus | |
| 1. n. The core, central part of something, around which other elements are assembled. | |
| 2. n. An initial part or version that will receive additions. | |
| This collection will form the nucleus of a new library. | |
| 3. n. (chemistry, physics) The massive, positively charged central part of an atom, made up of protons and neutrons. | |
| 4. n. (cytology) A large membrane-enclosed organelle found in eukaryotic cells which contains genetic material. | |
| 5. n. (neuroanatomy) A ganglion, cluster of many neuronal bodies where synapsing occurs. | |
| 6. n. (phonetics, phonology) The central part of a syllable, most commonly a vowel. | |
