Anlage, Kern, NMR, alpha particle, antibaryon, antilepton, antimeson, atomic nucleus
, atomic particle, axiom, axis, baryon, basichromatin, beta particle, bud, center, center of action, center of gravity, centroid, centrum, chromatin, chromatin strands, core, dead center, diameter, diaphragm, egg, electron, elementary particle, elixir, embryo, epicenter, equator, essence, essential, flower, focus, fundamental, germ, germen, gist, gravamen, heart, heterochromatin, hub, hypostasis, inner essence, interior, karyosome, karyotin, kernel, lepton, loins, macronucleus, marrow, mean, meat, median, medulla, meganucleus, meson, metacenter, micronucleus, middle, midmost, midriff, midst, nave, navel, neutron, nub, nuclear force, nuclear magnetic resonance, nuclear particle, nuclear resonance, nucleolus, nucleon, nucleosynthesis, nuts and bolts, omphalos, ovum, photon, pith, pivot, plasmosome, postulate, principle, proton, quid, quiddity, quintessence, rudiment, sap, seed, soul, spark, spermatozoon, spirit, storm center, strangeness, strong interaction, stuff, substance, the nitty-gritty, thick, thick of things, triton, umbilicus, valence electron, waist, waistline, zone
importance, consequence, moment, prominence, consideration, mark, materialness, import, significance, concern, emphasis, interest, greatness, superiority, notability, weight, value, usefulness, 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, cardinal point, substance, gist, 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, cream, salt, core, kernel, heart, nucleus
, keynote, keystone, corner stone, trump card, salient points, top sawyer, first fiddle, prima donna, chief, triton among the minnows, 'it', important, of importance, momentous, material, to the point, not to be overlooked, not to be despised, not to be sneezed at, egregious, weighty, of note, notable, prominent, salient, signal, memorable, remarkable, unforgettable, worthy of remark, worthy of notice, never to be forgotten, stirring, eventful, grave, serious, earnest, noble, grand, solemn, impressive, commanding, imposing, urgent, pressing, critical, instant, paramount, essential, vital, all-absorbing, radical, cardinal, chief, main, prime, primary, principal, leading, capital, foremost, overruling, of vital importance in the front rank, first-rate, superior, considerable, marked, rare, significant, telling, trenchant, emphatic, pregnant, tanti, materially, in the main, above all, kat' exochin, par excellence, to crown all, to beat all, expende Hannibalem!.
middle, midst, mediety, mean, medium, middle term, center &c, mid-course, mezzo termine, juste milieu, halfway house, nave, navel, omphalos, nucleus
, nucleolus, equidistance, bisection, half distance, equator, diaphragm, midriff, intermediate, middle, medial, mesial, mean, mid, median, average, middlemost, midmost, mediate, intermediate, equidistant, central, mediterranean, equatorial, homocentric, in the middle, midway, halfway, midships, amidships, in medias res.
cause, origin, source, principle, element, occasioner, prime mover, primum mobile, vera causa, author, mainspring, agent, leaven, groundwork, foundation, spring, fountain, well, font, fountainhead, spring head, wellhead, fons et origo, genesis, descent, remote cause, influence, pivot, hinge, turning point, lever, crux, fulcrum, key, proximate cause, causa causans, straw that breaks the camel's back, ground, reason, reason why, why and wherefore, rationale, occasion, derivation, final cause, les dessous des cartes, 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, caused, causal, original, primary, primitive, primordial, aboriginal, protogenal, radical, embryonic, embryotic, in embryo, in ovo, seminal, germinal, at the bottom of, connate, having a common origin, because, behind the scenes, causa latet vis est notissima, felix qui potuit rerum cognoscere causas.
centrality, centricalness, center, middle, focus, core, kernel, nucleus
, nucleolus, heart, pole axis, bull's eye, nave, navel, umbilicus, backbone, marrow, pith, vertebra, vertebral column, hotbed, concentration, centralization, symmetry, center of gravity, center of pressure, center of percussion, center of oscillation, center of buoyancy, metacenter, central, centrical, middle, azygous, axial, focal, umbilical, concentric, middlemost, rachidian, spinal, vertebral, middle, midst, centrally.