1. [ noun ] (anatomy,zoology) a part of the cell containing DNA and RNA and responsible for growth and reproduction
Synonyms: karyon cell_nucleus
Related terms: organelle subthalamic_nucleus pronucleus micronucleus cell nucleolus linin achromatin chromatin chromosome nucleoplasm
2. [ noun ] a small group of indispensable persons or things
Synonyms: core core_group

"five periodicals make up the core of their publishing program"

Related terms: set cadre
3. [ noun ] (physics,nuclear physics) the positively charged dense center of an atom
Related terms: center atom nucleon
4. [ noun ] (anatomy,zoology,histology) any histologically identifiable mass of neural cell bodies in the brain or spinal cord
Related terms: neural_structure dentate_nucleus
5. [ noun ] (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail
Related terms: center comet astronomy
Similar spelling:   Nuckles