nucleus

nucleus Definition

nu·cleus (no̵̅o̅′klē əs, nyo̵̅o̅′-)

noun pl. -·clei′--ī′ or -·cle·uses

a thing or part forming the center around which other things or parts are grouped or collected; core
anything serving as a center of growth or development the nucleus of a library
Anat. a group of nerve cells in the brain or spinal column
Astron. the bright central part of the head of a comet
Biol. the central, usually spherical or oval mass of protoplasm present in most plant and animal cells, containing most of the hereditary material and necessary to such functions as growth, reproduction, etc.
Bot. the central point in a starch grain
Chem., Physics the central part of an atom, the fundamental particles of which are the proton and neutron, except for hydrogen, which is usually composed of one proton only: it carries a positive charge and constitutes almost all of the mass of the atom
Phonet. the most sonorous portion of a syllable, usually a vowel
Organic Chem. a fundamental, stable arrangement of atoms that may occur in many compounds by atomic substitution without structural change, as the benzene ring

Etymology: ModL < L, a nut, kernel, for nuculeus, dim. < nux (gen. nucis), nut

nucleus Synonyms

nucleus Usage Examples

Converse of object

deform: Macroscopically, or classically, deformed nuclei can rotate ever more faster to produce a collective spin.

Adjective modifier

galactic: The may also contain an active galactic nucleus at their center.
suprachiasmatic: These are all regulated from an area of the brain called the suprachiasmatic nucleus, which is in the hypothalamus.
subthalamic: These electrical pulses are delivered through the extension and through the lead to the globus pallidus or subthalamic nucleus in the brain.
atomic: A proton in an atomic nucleus has an equal positive charge.
caudate: Note the red dot in the white matter just left of the caudate nucleus in the upper middle of the left hemisphere.
arcuate: In 2002, they examined the region of the brain's hypothalamus containing the arcuate nucleus, or ARC.

Modifies a noun

accumbens: Rats without damage to the nucleus accumbens showed a tendency to wait for the bigger reward.
pulposus: Nucleus pulposus is the light colored area within the annulus fibrosus.

Noun used with modifier

raphe: The most prominent modulatory input that CN neurons receive originates from serotoninergic neurons of raphe nuclei.
helium: The alpha particle is a helium nucleus - one of the products of a nuclear fission.
condensation: Thereby their optical properties, their efficiency to act as condensation nuclei and their lifetime with respect to deposition processes can be affected.
interphase: The copy number of chromosomes 7 and 17 was determined in interphase nuclei on intact 6 mu m tissue sections.
halo: Theories of halo nucleus scattering often use an approximation in which the halo is appeared frozen during the collision.
hydrogen: In 1920 he speculated that hydrogen nuclei were a building block of all nuclei.

Possessives

comet: The SOHO imaging shows sunlight reflecting off gas and dust from the comet's nucleus and hydrogen solar wind from the sun.

Preposition: of

amygdala: First, if we take a look at the lateral nucleus of the amygdala.
atom: The nucleus of a hydrogen atom is a proton.
comet: The supposed nucleus of the comet is the bright center of the coma.
galaxy: Under reasonably dark skies, a small telescope will show the nuclei of the two galaxies separated by 4.5 minutes of arc.

Browse dictionary entries near nucleus