nucleus
n. countablen. the central and most important part of an object or group. In science, it is the middle part of a cell or an atom that controls everything else.
n. the central core of an entity, serving as the basis for its activity and growth. In biology, it is the membrane-bound organelle containing genetic material; in physics, it is the positively charged central region of an atom.
The nucleus of the atom contains protons and neutrons.
A small nucleus of dedicated activists formed the heart of the movement and organized the first protests.
While the cytoplasm handles many metabolic tasks, the nucleus acts as the command center of the cell, housing the DNA required for replication and protein synthesis.
Learned borrowing from Latin nucleus (“kernel, core”). The earliest uses refer to the head of a comet and the kernel of a seed, both recorded in Lexicon Technicum in 1704. The sense in atomic physics was coined by British scientist Michael Faraday in 1844 in a theoretical meaning.
The plural form is 'nuclei'.
The nucleuses of the cellsThe nuclei of the cellsThe word follows Latin pluralization rules; 'nuclei' is the standard plural form in scientific contexts.