most serious

ADJECTIVE

somber, humorless

Synonyms

STRONGEST

deliberate genuine honest severe sincere thoughtful

STRONG

sober

WEAK

austere bound bound and determined businesslike cold sober contemplative deadpan determined downbeat earnest funereal go for broke grave grim intent long-faced meditative no-nonsense pensive pokerfaced reflective resolute resolved sedate set solemn staid steady stern unhumorous unsmiling weighty

Antonyms

STRONGEST

deceptive dishonest false insincere misleading untrustworthy

WEAK

flippant funny happy light minor trivial unimportant unserious

ADJECTIVE

crucial, weighty

Synonyms

STRONGEST

dangerous deep difficult far-reaching grievous important major meaningful severe significant tough urgent

WEAK

arduous fateful fell formidable grave grim hard heavy laborious meaning business menacing momentous no joke no laughing matter of consequence operose out for blood playing hard ball pressing smoking sobering strenuous strictly business threatening ugly unamusing unhumorous worrying

Antonyms

STRONGEST

calm easy facile friendly insignificant little meaningless minor small trivial unimportant worthless

WEAK

flippant funny happy light unserious

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Anyone who knows a farmer has heard stories of the “worst year ever” — but now American farmers are facing their most serious crisis since the 1980s.

From MarketWatch • May 4, 2026

Google’s TPUs are the most serious competition to Nvidia in the AI chip sector so far.

From Barron's • Apr. 21, 2026

And his most serious back surgery took place only six months ago.

From Los Angeles Times • Apr. 8, 2026

The CGL was a haven for the most serious weeknight warriors in the Upper Midwest—and it was run by none other than the first Kon Knueppel, Kon II’s father.

From The Wall Street Journal • Apr. 8, 2026

This sounded serious, so I put on my most serious, problem-solving face.

From "The World According to Humphrey" by Betty G. Birney