primary, capital; paramount, preeminent, premier, supreme, first, foremost, head, headmost, top, topmost; leading, crowning, ruling, overruling, prevailing; uppermost, important, most important, predominant, dominant; great, star, arch, banner, ranking, sovereign; most, utmost, major, maximum, maximal; substantial, sizable, considerable, large, big; powerful, strong, mighty, forceful, puissant; total, full, comprehensive, plenary.
2. essential, requisite, vital, necessary, indispensable, unexpendable; critical, crucial, consequential, pivotal; exigent, instant, pressing, urgent, imperative, high-priority; marked, signal, salient, notable, memorable; outstanding, remarkable, special, especial, particular.
3. sheer, brute, pure, dead, downright, consummate; utmost, utter, total, absolute, complete, out-and-out; direct, plain, bare, stark.
4. wide, vast, immense, broad; extensive, expansive, widespread, spacious, roomy, spread out, outspread. -n. 5. conduit, pipe, pipeline, duct, aqueduct, channel, canal; gutter, runnel, sewer, trough, shoot, chute; sluice, lock, floodgate, watergate, weir.
6. majority, bulk, mass, gross; substance, preponderance, meat, marrow; kernel, core, heart, nucleus, key, gist.
7. strength, power, force, might, potency, puissance; energy, vitality, vim, vigor; forcefulness, powerfulness, vehemence, virility, virulence.
8. Literary, sea, ocean, ocean blue, high seas, the open ocean, the deep, the seven seas, the bounding main; the deep blue sea, the vasty deep, the briny deep, the briny, SI. the drink, the watery waste.
9. in the main chiefly, principally. See - mainly.
mainland, n. main, principal land, continent, continental land.
mainly, adv. chiefly, principally, particularly, especially, primarily; mostly, for the most part, in the main, on the whole, by and large; overall, all in all, all things considered, on balance, in the long run, to all intents and purposes; substantially, effectually, effectively, essentially, for all practical purposes; generally, usually, predominantly, in general, as a rule; commonly, broadly, routinely, as a matter of course; to the greatest extent, above all, to a large degree.
mainspring, n. 1. principal spring, wheelwork, inner spring, essential part.
2. chief motive, impelling cause, impulse, prime motivation; source, origin, wellspring, fountainhead; ground, basis, key, keystone, root; prime mover, chief agent, most essential worker, author, generator, dynamo, Inf. sparkplug.
mainstay, n. chief support, principal support, main strength; chief reliance, anchor, sheet anchor, Inf. anchor to windward, anchorman; prop, staff, refuge, security; foundation, base, substructure; rock, Inf. rock of Gibraltar, reliable person, Atlas.
maintain, v. 1. continue, keep going, retain, pro long, keep alive, keep living, keep in existence; cherish, nurture, nurse, nourish, sustain, feed; support, support financially, Inf. keep, Inf. stake, Inf. grubstake, Inf. carry; hold up, uphold, support, bolster up, brace, shore up, truss, buttress, prop, prop up, stay.
2. keep intact, preserve, keep up, save from decay, keep in good condition; care for, take good care of, groom, conserve.
3. affirm, testify, attest, vouch, avouch, asseverate, witness, warrant; insist, hold, contend, profess; acknowledge, admit, give credence to, give currency to, certify; say, assert, aver, allege, claim; declare, state, set forth, annunciate, announce; publish, publish abroad, air, vent, ventilate, blow; propagate, circulate, spread, spread abroad, diffuse; put forward, put forth, issue, broach, utter; broadcast, shout from the rooftops, herald, blazon abroad, publicize.