Synonyms for Serious:
full-grown, of age, virile, adult, reasonable, nubile, mature, developed.
•crucial, weighty (adjective)
difficult, dangerous, meaningful, arduous, grievous, deep, pressing, tough, laborious, momentous, major, hard, sobering, significant, important.
important, momentous, salient, heavyweight, influential, notable, central, big-name, high-powered, fundamental, big, critical, substantial, earthshaking, distinguished, high, major, considerable, big-wig, crucial, grave, vital, eminent, pivotal, prominent, significant, meaningful, consequential, key, noteworthy, world-shaking.
devoted, deliberate, tenacious, spunky, tireless, persistent, staunch, zealous, reliable, courageous, dauntless, bold, resolved, persevering, valiant, insistent, unwavering, strong-willed, committed, dedicated, plucky, thorough, relentless, unchangeable, unyielding, resolute, bullheaded, constant, intent, indomitable, iron-willed, strong-minded, ruthless, diligent, unshakeable, steadfast, loyal, true, determined, steady, inexorable, indefatigable, steely, unbending, decisive, implacable, earnest, willing, faithful, uncompromising, stubborn, unflinching, dogged, stern, headstrong, tough, decided, firm, set, hearty, fearless.
•somber, humorless (adjective)
solemn, sedate, deliberate, staid, sincere, severe, grave, set, determined, thoughtful, intent, stern, sober, steady, resolved, funereal, earnest, resolute, no-nonsense, businesslike.
n.large, enormous, pressing, widely, extensive, high, big, huge, great. actively, complicit, be harnessed to, staid, in the process of doing something, engaged, active, attitude, involved, submerged, concerned. ruinous, damaging, sobersided, work, disastrous, injurious, businesslike, no-nonsense, harmful. anxious, upset, worried, troubled, on edge, nervous, alarmed, frightened, tense, uneasy, help. cohabit, fool around, go together, carry on, court, cheat, date, go with, dally with, go out. humorlessly, officious, funereal, substantial, deep, stolid.
involved, stolid, complicit, actively, submerged, sobersided, officious, engaged. staid, tall, concerned, uphill, arduous, tense. anxious, laborious. active. deep. •injurious
•matter of fact