serious
adjective
se·ri·ous ˈsir-ē-əs 
1
: thoughtful or subdued in appearance or manner : sober
a quiet, serious girl
2
a
: requiring much thought or work
serious study
b
: of or relating to a matter of importance
a serious play
3
a
: not joking or trifling : being in earnest
a serious question
b
archaic : pious
c
: deeply interested : devoted
a serious musician
4
a
: not easily answered or solved
serious objections
b
: having important or dangerous possible consequences
a serious injury
5
: excessive or impressive in quality, quantity, extent, or degree
serious stereo equipment
making serious money
serious drinking
seriousness noun
Synonyms
- earnest
- grave
- humorless
- no-nonsense
- po-faced [British]
- sedate
- severe
- sober
- sobersided
- solemn
- staid
- uncomic
- unsmiling
- weighty
See all Synonyms & Antonyms 
Example Sentences
“You sound terrible.” “It's just a bad cold. Nothing serious.” For my brother, not going to college was a serious mistake. Crime is a serious problem in this neighborhood. The team is a serious contender for the championship. If you want to quit smoking, you have to make a serious effort. They had a serious conversation about their relationship. a serious novel about modern life The story raises serious questions about our system of justice. Dog shows are a serious business. She is a serious cyclist who rides 200 miles each week. See More
Recent Examples on the Web The authors reveal a set of exchanges between Trump and Attorney General William Barr that suggest the president was truly serious about his tweet threats to lock up election rival Joe Biden. 
Jacob S. Hacker, Washington Post, 14 Sep. 2022 At the end of the call, Finebaum asked Skip Golding if his threat was serious. Mark Heim | Mheim@al.com, al, 13 Sep. 2022 Kourtney Kardashian Barker is serious about health and wellness when her kids are concerned. Angela Andaloro, Peoplemag, 13 Sep. 2022 The charges are serious given the ongoing debate over the value of a typical college degree in the humanities, given tuition has been among the largest drivers of national inflation. Christiaan Hetzner, Fortune, 12 Sep. 2022 All that will take some sorting out before next week to see how serious the injuries are. Dave Hyde, Sun Sentinel, 11 Sep. 2022 Company executives and some careers experts warn that checking out at work could have serious long-term consequences for employees’ careers, as well as their employers. Mariah Espada, Time, 9 Sep. 2022 The decision could have serious consequences given the scale of the United Kingdom's cost-of-living crisis. Alexander Smith, NBC News, 9 Sep. 2022 The statement from Buckingham Palace, issued at 12.30pm local time, was unprecedented and experienced broadcasters immediately realized the situation was serious. K.j. Yossman, Variety, 9 Sep. 2022 See More
Jacob S. Hacker, Washington Post, 14 Sep. 2022 At the end of the call, Finebaum asked Skip Golding if his threat was serious. Mark Heim | Mheim@al.com, al, 13 Sep. 2022 Kourtney Kardashian Barker is serious about health and wellness when her kids are concerned. Angela Andaloro, Peoplemag, 13 Sep. 2022 The charges are serious given the ongoing debate over the value of a typical college degree in the humanities, given tuition has been among the largest drivers of national inflation. Christiaan Hetzner, Fortune, 12 Sep. 2022 All that will take some sorting out before next week to see how serious the injuries are. Dave Hyde, Sun Sentinel, 11 Sep. 2022 Company executives and some careers experts warn that checking out at work could have serious long-term consequences for employees’ careers, as well as their employers. Mariah Espada, Time, 9 Sep. 2022 The decision could have serious consequences given the scale of the United Kingdom's cost-of-living crisis. Alexander Smith, NBC News, 9 Sep. 2022 The statement from Buckingham Palace, issued at 12.30pm local time, was unprecedented and experienced broadcasters immediately realized the situation was serious. K.j. Yossman, Variety, 9 Sep. 2022 See More Word History
Etymology
Middle English seryows, from Anglo-French or Late Latin; Anglo-French serious, from Late Latin seriosus, alteration of Latin serius weighty, serious; probably akin to Old English swǣr heavy, sad
First Known Use
15th century, in the meaning defined at sense 1
Phrases Containing serious
Kids Definition
serious
adjective
se·ri·ous ˈsir-ē-əs
1
: not joking or funny
a serious drama
2
: being such as to cause distress or harm
a serious accident
3
: thoughtful or quiet in appearance or manner
a serious person
4
: requiring much thought or work
a serious task
Medical Definition
serious
adjective
se·ri·ous ˈsir-ē-əs
: having important or dangerous possible consequences
a serious injury
serious
adjective
1
as in solemn
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 & Similar Words
Relevance
- solemn
- severe
- earnest
- professional
- stern
- humorless
- harsh
- sober
- distinguished
- unsmiling
- po-faced
- grave
- no-nonsense
- weighty
- uncomic
- sedate
- sobersided
- staid
- strict
- grim
- businesslike
- dignified
- serious-minded
- gloomy
- elevated
Antonyms & Near Antonyms
- humorous
- joking
- playful
- flippant
- jocular
- facetious
- funny
- ridiculous
- comical
- light
- ludicrous
- hysterical
- hilarious
- laughable
- comic
- ludic
- frivolous
- flip
- riotous
- hysteric
- uproarious
- farcical
- lighthearted
- jesting
- goofy
- antic
- kittenish
- risible
- droll
- silly
- screaming
- absurd
- foolish
- puerile
- insane
- crazy
- mad
- unwise
- sidesplitting
- zany
- lunatic
- harebrained
- nutty
- wacky
- scatterbrained
- whacky
- fatuous
- nonsensical
- preposterous
- asinine
- flighty
- daft
- kooky
- loony
- sappy
- jerky
- light-headed
- brainless
- senseless
- witless
- daffy
- cuckoo
- featherbrained
- balmy
- dotty
- screwball
- cockeyed
- looney
- kookie
- weak-minded
- half-witted
2
as in important
having a matter of importance as its topic a very serious film that dealt with the aftermath of the Gulf War Synonyms & Similar Words
- important
- major
- big
- significant
- meaningful
- substantial
- heavy
- grave
- weighty
- solid
- momentous
- consequential
- material
- portentous
- eventful
Antonyms & Near Antonyms
- light
- unserious
- minor
- little
- small
- trivial
- silly
- slight
- frivolous
- insignificant
- unimportant
- lite
- Mickey Mouse
3
as in dangerous
involving potential loss or injury a serious accident Synonyms & Similar Words
- dangerous
- hazardous
- risky
- perilous
- grievous
- precarious
- menacing
- unsafe
- threatening
- grave
- unhealthy
- treacherous
- fatal
- jeopardizing
- random
- parlous
- adverse
- uncertain
- detrimental
- unpleasant
- venturesome
- bad
- destructive
- harmful
- chance
- lethal
- deadly
- sickening
- nasty
- dire
- ugly
- insecure
- dicey
- fell
- injurious
- distressing
- pernicious
- deleterious
- haphazard
- murderous
- ill
- wicked
- killer
- malignant
- evil
- mortal
- hurtful
- inimical
- noxious
- fateful
- ultrahazardous
- deathly
- baneful
- baleful
- pestilent
Antonyms & Near Antonyms
- harmless
- innocuous
- innocent
- good
- safe
- beneficial
- nonthreatening
- advantageous
- nonhazardous
- unthreatening
- ultrasafe
Synonym Chooser
Some common synonyms of serious are earnest, grave, sedate, sober, solemn, and staid. While all these words mean "not light or frivolous," serious implies a concern for what really matters.
a serious play about social injustice
Although the words earnest and serious have much in common, earnest suggests sincerity or often zealousness of purpose.
an earnest reformer
While in some cases nearly identical to serious, grave implies both seriousness and dignity in expression or attitude.
read the proclamation in a grave voice
While the synonyms sedate and serious are close in meaning, sedate implies a composed and decorous seriousness.
remained sedate amid the commotion
The words sober and serious are synonyms, but do differ in nuance. Specifically, sober stresses seriousness of purpose and absence of levity or frivolity.
a sober look at the state of our schools
The synonyms solemn and serious are sometimes interchangeable, but solemn suggests an impressive gravity utterly free from levity.
a sad and solemn occasion
In some situations, the words staid and serious are roughly equivalent. However, staid suggests a settled, accustomed sedateness and prim self-restraint.
a quiet and staid community