1The central and most important part of an object, movement, or group, forming the basis for its activity and growth.‘the nucleus of a British film-producing industry’
core, centre, central part, most important part, heart, nub, hub, middle, midpoint, eye, kernel, focus, focal point, pivot, cruxView synonyms
- ‘Senate House and a nucleus of colleges were built in Bloomsbury in the late 1930s.’
- ‘The nucleus of the global movement against injustice will not - cannot, should not - be found in the centers of global privilege.’
- ‘It was a medieval library serving as the nucleus of a range of activities in the fields of art, religion, history and literature.’
- ‘In addition to being the center of religious training and worship, the church served as the nucleus of social activities and a conduit for the dispersion of social services.’
- ‘If this proposal is accepted, the government together with the St Lucian organizations could have an extension of the mission in Brooklyn and an important nucleus for the St Lucian community.’
- ‘Fairs form the nucleus for frenetic autumn activity in London and New York, while a princely collection is auctioned at a fairy-tale castle in Germany’
- ‘It was happy to see the destruction of the Polish resistance movement, which had formed the nucleus of the support for the Polish government-in-exile.’
- ‘By the end of the 1850s a nucleus of business houses had been established.’
- ‘The nucleus of the future Impressionist movement was born.’
- ‘And at the moment there is not even the nucleus of a movement to achieve that.’
- ‘At school, Qaddafi participated in a small group of politically active friends - a group which was eventually to form the nucleus of the Free Officers Movement.’
- ‘Without the ‘woman’, there will be a crippling lacuna, since it is her nurturing instinct that anchors the family making her a nucleus around which every member rallies.’
- ‘The Manchester centre is the nucleus of a hi-tech surveillance system and features an 18-metre monitor wall that can display up to 180 high-resolution images.’
- ‘His own drawings form the nucleus of an important collection of architectural drawings.’
- ‘In the middle of these green acres, a modest cluster of white greenhouses make up the nucleus of daily activity.’
- ‘He built the famous Stone House at Ooty that formed the nucleus of Government offices and is now part of the Government Arts College.’
- ‘In 1911, the first dairy cows and other livestock arrived to become the nucleus of USDA's animal husbandry research activities.’
- ‘Christine Maggiore is the outspoken nucleus of a movement to help HIV-positive mothers who question medication.’
- ‘These embryonic communities created an important nucleus for post-war migration, which was fuelled by economic factors.’
- ‘As already stated, the placing of bets and payment of winnings form the nucleus of the gambling activity.’
- 1.1Physics The positively charged central core of an atom, consisting of protons and neutrons and containing nearly all its mass.
- ‘Every atomic nucleus consists of a certain number of protons, strongly bound to a certain number of neutrons.’
- ‘The harmless radio waves excite protons that form the nuclei of hydrogen atoms in the body.’
- ‘Electrons produce a small magnetic field as they spin and orbit the nucleus of an atom.’
- ‘Most atomic nuclei consist of clusters of protons and neutrons (which have no electrical charge).’
- ‘Electrons are found in clouds that surround the nucleus of an atom.’
- 1.2Biology A dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material.
- ‘Dense granules surrounding the nucleus are probably cytoplasmic organelles.’
- ‘The cells had round or oval vesicular nuclei with multiple prominent nucleoli.’
- ‘The cells possessed eosinophilic cytoplasm, well-defined cell borders, and vesicular nuclei with small, conspicuous nucleoli.’
- ‘The cells were characterized by large vesicular nuclei with single large nucleoli.’
- ‘Further, interphase nuclei appeared disintegrated and some mitotic figures were clumped together.’
- 1.3Anatomy A discrete mass of grey matter in the central nervous system.
- ‘Axons travel from the neurons located in nuclei within the brain stem via the cranial nerves without synaptic interruption to the motor end plates on the striated muscle.’
- ‘The trochlear nerve nuclei are located ventral to the mesencephalic aqueduct.’
- ‘These effects are produced by fibres projecting from the hypothalamus to parasympathetic nuclei in the brain stem, and to sympathetic centres in the spinal cord.’
- ‘The term extrapyramidal system refers to the basal ganglia and several brain stem nuclei with which they are connected.’
- ‘The pontocerebellar fibers connect pontine nuclei with the cerebellar cortex of the opposite side, via the middle cerebellar peduncles.’
- 1.4Astronomy The solid part of a comet's head.
- ‘Another difficulty that must be resolved is the current uncertainty about the consistency of cometary nuclei.’
- ‘Indeed, the outermost asteroids show similarities with the cometary nuclei observed far from the Sun.’
- ‘The spacecraft's point of view now captures the shadowed side of the comet's nucleus.’
- ‘Sometimes, the stresses are strong enough to break off chunks of the comet's nucleus.’
- ‘The spacecraft will orbit the comet's nucleus.’
Early 18th century: from Latin, literally ‘kernel, inner part’, diminutive of nux, nuc- ‘nut’.
We take a look at several popular, though confusing, punctuation marks.