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nucleus

nu·cle·us

nucleus

 
pronunciation:
nu kli s
features:
Word Explorer
part of speech: noun
inflections: nuclei, nucleuses
definition 1: the central, essential, or most active part around which other parts are grouped.
Main Street is the nucleus of the town.
synonyms:
core, hub
similar words:
center, heart, kernel, marrow, navel, pith, soul
definition 2: the part of a cell that contains chromosomes, which control growth and reproduction in most living things.
definition 3: the central part of an atom, which has a positive charge.
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See
  cell, physics