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adjective se·ri·ous \ˈsir-ē-əs\

Simple Definition of serious

  • : having an important or dangerous possible result

  • : involving or deserving a lot of thought, attention, or work

  • : giving a lot of attention or energy to something

Source: Merriam-Webster's Learner's Dictionary

Full Definition of serious

  1. 1 :  thoughtful or subdued in appearance or manner :  sober <a quiet, serious girl>

  2. 2a :  requiring much thought or work <serious study>b :  of or relating to a matter of importance <a serious play>

  3. 3a :  not joking or trifling :  being in earnest <a serious question>b archaic :  piousc :  deeply interested :  devoted <a serious musician>

  4. 4a :  not easily answered or solved <serious objections>b :  having important or dangerous possible consequences <a serious injury>

  5. 5 :  excessive or impressive in quality, quantity, extent, or degree <serious stereo equipment> <making serious money> <serious drinking>

seriousness noun

Examples of serious in a sentence

  1. You sound terrible. It's just a bad cold. Nothing serious.

  2. For my brother, not going to college was a serious mistake.

  3. Crime is a serious problem in this neighborhood.

  4. The team is a serious contender for the championship.

  5. If you want to quit smoking, you have to make a serious effort.

  6. They had a serious conversation about their relationship.

  7. a serious novel about modern life

  8. The story raises serious questions about our system of justice.

  9. Dog shows are a serious business.

  10. She is a serious cyclist who rides 200 miles each week.

Origin of serious

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

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>.

Rhymes with serious

SERIOUS Defined for Kids


adjective se·ri·ous \ˈsir-ē-əs\

Definition of serious for Students

  1. 1 :  not joking or funny <a serious drama>

  2. 2 :  being such as to cause distress or harm <a serious accident>

  3. 3 :  thoughtful or quiet in appearance or manner <a serious person>

  4. 4 :  requiring much thought or work <a serious task>

seriousness noun

Medical Dictionary


adjective se·ri·ous \ˈsir-ē-əs\

Medical Definition of serious

  1. :  having important or dangerous possible consequences <a serious injury>

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).


to dishevel or rumple

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