Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

Thesaurus

serious

adjective

Synonyms and Antonyms of serious

1 not joking or playful in mood or manner
  • I'm serious when I say that you need to be aware of your surroundings when driving.
Synonyms of serious

earnest, grave, humorless, no-nonsense, sedate, severe, sober, 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
Antonyms of serious

facetious, flip, flippant, humorous, jesting, jocular, joking, playful
2 having a matter of importance as its topic
  • a very serious film that deals with our justice system
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, little, minor, silly, slight, small, trivial, unimportant
Antonyms of serious

light, unserious
3 involving potential loss or injury
  • a serious accident
Synonyms of serious

dangerous, grave, grievous, hazardous, jeopardizing, menacing, parlous, perilous, risky, threatening, unhealthy, unsafe, venturesome
Words Related to serious

dicey, insecure, precarious, treacherous, uncertain

ultrahazardous

chance, haphazard, random

adverse, bad, baleful, baneful, deleterious, detrimental, evil, harmful, hurtful, ill, inimical, injurious, malignant, nasty, noxious, pernicious, pestilent

deadly, deathly, destructive, dire, fatal, fateful, lethal, mortal, murderous
Near Antonyms of serious

advantageous, beneficial, good

ultrasafe
Antonyms of serious

harmless, innocent, innocuous, nonhazardous, nonthreatening, safe, unthreatening

Synonym Discussion of serious

serious, grave, solemn, sedate, staid, sober, earnest mean not light or frivolous. serious implies a concern for what really matters.
    • a serious play about social injustice
grave implies both seriousness and dignity in expression or attitude.
    • read the proclamation in a grave voice
solemn suggests an impressive gravity utterly free from levity.
    • a sad and solemn occasion
sedate implies a composed and decorous seriousness.
    • remained sedate amid the commotion
staid suggests a settled, accustomed sedateness and prim self-restraint.
    • a quiet and staid community
sober stresses seriousness of purpose and absence of levity or frivolity.
    • a sober look at the state of our schools
earnest suggests sincerity or often zealousness of purpose.
    • an earnest reformer

Learn More about serious

  1. See words that rhyme with serious Dictionary: Definition of serious Medical Dictionary: Definition of serious Spanish Central: Translation of serious Nglish: Translation of serious for Spanish speakers Britannica English: Translation of serious for Arabic speakers

Seen and Heard

What made you want to look up serious? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

Ask the Editors

Word Games