nucleus
UK: ˈnjuːkliəs | US: ˈnuːkliəs
n. 1. The central and most important part of an object, movement, or group, forming the basis for its activity and growth.
n. 2. (Biology) A dense organelle present in eukaryotic cells, containing genetic material.
n. 3. (Physics) The positively charged central core of an atom, consisting of protons and neutrons.
Derived from Latin nucleus ("kernel, inner part"), a diminutive of nux ("nut"). The term originally referred to the edible core of a nut, later metaphorically extended to denote the central or essential part of anything. In scientific contexts (18th–19th centuries), it was adopted to describe biological and atomic structures, emphasizing their foundational role—mirroring the logic of a nut's kernel as its vital center.
The nucleus of the cell controls genetic expression.
The team formed the nucleus of a new research initiative.
Protons and neutrons are bound together in the atom's nucleus.
The debate centered around the nucleus of the argument.
Ancient cities often grew around a nucleus of trade and governance.