A part of the cell containing DNA and RNA and responsible for growth and reproduction.

synonyms: cell nucleus, karyon.

Roget 153: cause, origin, source, principle, element; occasioner^†, prime mover, primum mobile [Lat.]; vera causa [Lat.]; author etc. (producer) 164; mainspring; agent; leaven; groundwork, foundation etc. (support) 215.    spring, fountain, well, font; fountainhead, spring head, wellhead; fons et origo [Lat.], genesis; descent etc. (paternity) 166; remote cause; influence.    pivot, hinge, turning point, lever, crux, fulcrum; key; proximate cause, causa causans [Lat.]; straw that breaks the camel's back.    ground; reason, reason why; why and wherefore, rationale, occasion, derivation; final cause etc. (intention) 620; les dessous des cartes [Fr.]; undercurrents.    rudiment.    egg, germ, embryo, bud, root, radix radical, etymon, nucleus, seed, stem, stock, stirps, trunk, tap-root, gemmule^†, radicle, semen, sperm.    nest, cradle, nursery, womb, nidus, birthplace, hotbed.    causality, causation; origination; production etc. 161.    ... show more

Roget 68: middle, midst, mediety^†, mean etc. 29; medium, middle term; center etc. 222, mid-course etc. 628; mezzo termine [It]; juste milieu [Fr.] etc. 628; halfway house, nave, navel, omphalos^†; nucleus, nucleolus.    equidistance^†, bisection, half distance; equator, diaphragm, midriff; intermediate etc. 228.    ... show more

Dutch: celkern, kern, nucleus
Polish: nukleus, jądro, jądro komórkowe

The positively charged dense center of an atom.

Dutch: atoomkern, kern, kerndeeltje, kiem, nucleus
Polish: jądro, jądro atomowe

A small group of indispensable persons or things.

synonyms: core, core group.

Roget 222: centrality, centricalness^†, center; middle etc. 68; focus etc. 74.    core, kernel; nucleus, nucleolus; heart, pole axis, bull's eye; nave, navel; umbilicus, backbone, marrow, pith; vertebra, vertebral column; hotbed; concentration etc. (convergence) 290; centralization; symmetry.    center of gravity, center of pressure, center of percussion, center of oscillation, center of buoyancy &c.; metacenter^†.    ... show more

Roget 642: importance, consequence, moment, prominence, consideration, mark, materialness.    import, significance, concern; emphasis, interest.    greatness etc. 31; superiority etc. 33; notability etc. (repute) 873; weight etc. (influence) 175; value etc. (goodness) 648; usefulness etc. 644.    gravity, seriousness, solemnity; no joke, no laughing matter; pressure, urgency, stress; matter of life and death.    memorabilia, notabilia^†, great doings; red-letter day.    great thing, great point; main chance, the be all and the end all" [Macbeth]; cardinal point; substance, gist etc. (essence) 5; sum and substance, gravamen, head and front; important part, principal part, prominent part, essential part; half the battle; sine qua non; breath of one's nostrils etc. (life) 359; cream, salt, core, kernel, heart, nucleus; keynote, keystone; corner stone; trump card etc. (device) 626; salient points.    top sawyer, first fiddle, prima donna [Sp.], chief; triton among the minnows; 'it' [U.S.].   " ... show more

astronomy The center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail.

Polish: jądro

Any histologically identifiable mass of neural cell bodies in the brain or spinal cord.

The central structure of the lens that is surrounded by the cortex.

synonym: lens nucleus.