serious

1 not joking or playful in mood or manner I'm serious when I say that no one should be walking in that neighborhood at night Synonyms of serious earnest, grave, humorless, no-nonsense, po-faced [British], sedate, severe, sober, sobersided, solemn, staid, uncomic, unsmiling, weighty Words Related to serious harsh, stern, strict; businesslike, professional; dignified, distinguished, elevated, serious-minded; gloomy, grim Near Antonyms of serious antic, comic, comical, droll, farcical, funny, hilarious, hysterical (also hysteric), laughable, light, light-headed, ludicrous, ridiculous, riotous, risible, screaming, sidesplitting, uproarious; featherbrained, flighty, frivolous, goofy, harebrained, lighthearted, puerile, scatterbrained; absurd, asinine, balmy, brainless, cockeyed, crazy, cuckoo, daffy, daft, dotty, fatuous, foolish, half-witted, insane, jerky, kooky (also kookie), loony (also looney), lunatic, mad, nonsensical, nutty, preposterous, sappy, screwball, senseless, silly, unwise, wacky (also whacky), weak-minded, witless, zany Antonyms of serious facetious, flip, flippant, humorous, jesting, jocular, joking, kittenish, ludic, playful

2 having a matter of importance as its topic a very serious film that dealt with the aftermath of the Gulf War Synonyms of serious grave, heavy, weighty Words Related to serious big, consequential, eventful, important, major, material, meaningful, momentous, portentous, significant, solid, substantial Near Antonyms of serious frivolous, insignificant, lite, little, Mickey Mouse, minor, silly, slight, small, trivial, unimportant Antonyms of serious light, unserious

3 involving potential loss or injury a serious accident Synonyms of serious grave, grievous, hazardous, jeopardizing, menacing, parlous, perilous, risky, dangerous, threatening, unhealthy, unsafe, venturesomeWords Related to serious dicey, insecure, precarious, treacherous, uncertain; ultrahazardous; chance, haphazard, random; distressing, sickening, unpleasant; ugly, wicked; adverse, bad, baleful, baneful, deleterious, detrimental, evil, harmful, hurtful, ill, inimical, injurious, malignant, nasty, noxious, pernicious, pestilent; deadly, deathly, destructive, dire, fatal, fateful, fell, killer, lethal, mortal, murderousNear Antonyms of serious advantageous, beneficial, good; ultrasafeAntonyms of serious harmless, innocent, innocuous, nonhazardous, nonthreatening, safe, unthreatening