Student Dictionary

2 entries found for nucleus.
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Main Entry: nu·cle·us
Pronunciation: primarystressn(y)ü-klemacron-schwas
Function: noun
Inflected Form(s): plural nu·clei /-klemacron-secondarystressimacr /; also -cle·us·es
Etymology: from modern Latin nucleus "the central part of something," from Latin nucleus "kernel," derived from nux "nut"
: a central point, group, or mass of something: as a : the small, brighter, and denser part of a galaxy or of the head of a comet b : a cell part that is characteristic of all living things with the exception of viruses, bacteria, and blue-green algae, that is necessary for heredity and for making proteins, that contains the chromosomes, and that is enclosed in a nuclear membrane c : a mass of gray matter or group of neurons in the central nervous system d : the central part of an atom that includes nearly all of the atomic mass and consists of protons and usually neutrons
[nucleus illustration]

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