Nucleus

Nucleus can mean:

• atomic nucleus, the collection of protons and neutrons in the center of an atom that carries the bulk of the atom's mass and positive charge
• cell nucleus, the membrane-bound subcellular organelle found in eukaryotes, visible via microscopy, which contains, primarily, the cell's chromosomes
• nucleus, a term in neuroanatomy used to describe a central nervous system structure composed mainly of gray matter that mediates electrical signaling within a particular subsystem
• comet nucleus, the solid core of a comet
• galaxy nucleus, the central region of a galaxy
• ice nucleus, the center of an ice crystal.
• cloud condensation nuclei, the basis for the development of a cloud droplet
• syllable nucleus, the central part of a syllable
• sentence nucleus, the syllable which receives the greatest stress in a word
• Nucleus CMS, an open-source weblog system
• the kernel of an operating system
• Nucleus RTOS, a brand of operating system

Etymology

Nucleus is New Latin, diminutive of the Latin nux (nut).