nucleus
nu-cle-us
noun
The central part of an atom that contains protons and neutrons.
"The nucleus of an atom is positively charged."
noun
The central part of a cell that contains most of its genetic material.
"The nucleus of a cell is surrounded by a membrane."
noun
A central or essential part of something.
"The nucleus of the team was its strong leadership."
Thesaurus
Synonyms: lens nucleus, core group, core, karyon, cell nucleus