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Showing results for serious.
Definitions

serious

[seer-ee-uhs] / ˈsɪər i əs /
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.

Helen and Lee decided to take Meg back to Wales but on the way, her symptoms became more serious and she was admitted to Southmead Hospital, in Bristol, where she died.

From BBC • Apr. 3, 2026

Most grew up in religious or at least morally serious families.

From The Wall Street Journal • Apr. 3, 2026

Mirman was hospitalized for serious injuries on Tuesday after being pulled out of the window of his Lucid Gravity that had caught fire after crashing into the Bedford Toll Plaza in New Hampshire.

From Los Angeles Times • Apr. 3, 2026

"It was noted that intense military action is leading to serious negative consequences not only regionally but also globally, including in the areas of energy, trade, and logistics," it added.

From Barron's • Apr. 3, 2026

But Mr. Grayson looked serious, so Bat reluctantly went to his seat.

From "A Boy Called Bat" by Elana K. Arnold

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.