Synonyms for Important:

adj.

all (adjective)
of import.
authoritative (adjective)
commanding, autocratic, imperious, powerful, impressive, dictatorial, potent, masterful, arrogant, effectual, effective, consequential, authoritative, influential, authoritarian, strong.
central (adjective)
pivotal.
eminent, influential, outstanding (adjective)
distinguished, effective, noteworthy, prominent, powerful, remarkable, aristocratic, illustrious, noble, talented, leading, extraordinary, grand, notable, well-known, noted, high-ranking, superior, solid, famous, potent, imposing, distinctive, honored.
far-reaching (adjective)
far-reaching.
important (adjective)
distinguished, earthshaking, salient, world-shaking, signal, big-name, critical, major, noteworthy, considerable, notable, eminent, grave, pivotal, influential, prominent, heavyweight, consequential, big-wig, far-reaching, serious, momentous, crucial, high-powered.
influential (adjective)
predominant, powerful, masterful, commanding, authoritative, senior, motivational, prejudicial, ruling, influential, leading, supreme, controlling.
life-and-death (adjective)
all-important, earthshaking.
portentous (adjective)
portentous.
powerful (adjective)
formidable, dominant.
relevant (adjective)
related, relevant.
respected (adjective)
honored.
substantial (adjective)
appreciable, united, palpable, substantive, material, physical, firm, solid, immanent, considerable, substantial, actual, sturdy, meaningful, real, tangible, bodily, significant.
valuable, substantial (adjective)
grave, pressing, critical, salient, necessary, heavy, exigent, vital, signal, meaningful, serious, determining, crucial, momentous, considerable, marked, large, principal, relevant, primary, STANDOUT, extensive, big, paramount, foremost, urgent, influential, weighty, great, chief, significant, material, decisive, conspicuous, ponderous, far-reaching, imperative.

n.

affect. important (noun)
eminent, burning, large, evidential, of import, noteworthy, in-chief, operative, valuable, momentous, prodigious, fundamental, principal, world-shattering, historic, big, strategic, alpha, consequential, polar, heavy, main, great, distinguished, influential, head, cardinal, eventful, authoritative, profound, boss, pivotal, primary, chief, of value, all-important, earthshaking, world-shaking, monumental, central, immodest, primal, most-valuable, copernican, key, measurable, life-or-death, remarkable, grievous, life-and-death, grave, critical, arch, of the essence, weighty, portentous, crucial, epochal, evidentiary, useful, epoch-making, decisive, top, probative, serious.

v.

distinguished (verb)
illustrious.
respected (verb)
honored.

Other synonyms:

conspicuous, urgent, big league. foremost, paramount. dominant. essential
necessary.
historic
historic.
importunate
pressing.
main
main.
necessary
imperative, vital.
pertinent
relevant.
primary
primary.
remarkable
remarkable.
renowned
famous.
useful
useful.

Usage examples for important

  1. It was important that no time should be lost. – Down the Slope by James Otis
  2. I have something important to say. – Guy Garrick by Arthur B. Reeve
  3. How important they have become to us, and how little, last summer, we could have dreamed of it. – Franklin Kane by Anne Douglas Sedgwick