- of, showing, or characterized by deep thought.
- of grave or somber disposition, character, or manner: a serious occasion; a serious man.
- being in earnest; sincere; not trifling: His interest was serious.
- requiring thought, concentration, or application: serious reading; a serious task.
- weighty or important: a serious book; Marriage is a serious matter.
- giving cause for apprehension; critical: The plan has one serious flaw.
- Medicine/Medical. (of a patient's condition) having unstable or otherwise abnormal vital signs and other unfavorable indicators, as loss of appetite and poor mobility: patient is acutely ill.
- that which is of importance, grave, critical, or somber: You have to learn to separate the serious from the frivolous.
Origin of serious
Synonyms for seriousSee more synonyms for on Thesaurus.com
Antonyms for serious
Related Words for nonseriouspetty, impractical, senseless, idiotic, foolish, pointless, barmy, childish, dizzy, empty-headed, facetious, flighty, flip, flippant, gay, giddy, harebrained, idle, juvenile, light
- grave in nature or disposition; thoughtfula serious person
- marked by deep feeling; in earnest; sincereis he serious or joking?
- concerned with important mattersa serious conversation
- requiring effort or concentrationa serious book
- giving rise to fear or anxiety; criticala serious illness
- informal worthy of regard because of substantial quantity or qualityserious money; serious wine
- informal extreme or remarkablea serious haircut
Word Origin for serious
Word Origin and History for nonserious
mid-15c., "expressing earnest purpose or thought" (of persons), from Middle French sérieux "grave, earnest" (14c.), from Late Latin seriosus, from Latin serius "weighty, important, grave," probably from a PIE root *swer- (4) "heavy" (cf. Lithuanian sveriu "to weigh, lift," svarus "heavy;" Old English swære "heavy," German schwer "heavy," Gothic swers "honored, esteemed," literally "weighty"). As opposite of jesting, from 1712; as opposite of light (of music, theater, etc.), from 1762. Meaning "attended with danger" is from 1800.
- Being of such import as to cause anxiety, as of a physical condition.