- 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
SynonymsSee more synonyms for serious on Thesaurus.com
Examples from the Web for unserious
“Benghazi was the definition of an intelligence failure,” Paul begins, dismissing the entire committee report as unserious.Rand Paul Won’t Let Benghazi Die
December 2, 2014
But upon the appointment of Klein to that role, he criticized the choice as “political” and unserious.Ron Klain Will Be the Best Ebola Czar Yet
Tim Mak, Abby Haglage
October 17, 2014
The Texas Republican practically bilked his donors by running the most unserious campaign in recent American history.Good Riddance to Steve Stockman, the Grifter Congressman Who Ran for Senate
March 4, 2014
The inmates of FX consider Viva to be effete, soft and unserious.My Week At An Austrian Fat Camp
October 27, 2013
It does, however, stand as one more sign of how unserious Congress has become about governing.Washington’s Silly Plan to Create a National Nurse
February 10, 2013
Still, we were both born as we are, and I've just as much right to be unserious as you have to be serious.The Matador of the Five Towns and Other Stories
His own father was an unscrupulous, unserious man, that was true, but at any rate he had given his son a human chance.The Sins of the Children
A lot of the girls have been sick a little with colds and small and unserious diseases in the past year.Mary Cary
Kate Langley Bosher
- 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 and History for unserious
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.