1. the central part of an atom that contains protons and neutrons
Usage: physics
2. the control center of a cell that contains genetic material
Usage: biology
3. the central or most important part of something around which other parts are grouped

Examples

• The nucleus of an atom is extremely small but contains most of its mass.
• Plant and animal cells both have a nucleus that controls cellular functions.
• The old library served as the nucleus of the downtown revitalization project.
• A small nucleus of dedicated volunteers started the charity organization.
• Scientists study the nucleus to understand atomic structure.
• The cell nucleus contains DNA that determines hereditary traits.
• The research team formed the nucleus of the new department.