Dictionary.com
definitions

serious

[seer-ee-uhs]
||

adjective

noun

that which is of importance, grave, critical, or somber: You have to learn to separate the serious from the frivolous.

RELATED CONTENT

Why so serious?
Read more in this article about some frequently asked questions and fun facts related to our definitions.
READ MORE
half your age plus seven
Read more in this article about some frequently asked questions and fun facts related to our definitions.
READ MORE

Origin of serious

1400–50; late Middle English < Latin sērius or Late Latin sēriōsus; see -ous, -ose1
Related formsse·ri·ous·ness, nounhalf-se·ri·ous, adjectivehalf-se·ri·ous·ly, adverbhalf-se·ri·ous·ness, nounnon·se·ri·ous, adjectivenon·se·ri·ous·ly, adverbnon·se·ri·ous·ness, nouno·ver·se·ri·ous, adjectiveo·ver·se·ri·ous·ly, adverbo·ver·se·ri·ous·ness, nounqua·si-se·ri·ous, adjectivequa·si-se·ri·ous·ly, adverbsu·per·se·ri·ous, adjectivesu·per·se·ri·ous·ly, adverbsu·per·se·ri·ous·ness, nounul·tra·se·ri·ous, adjectiveul·tra·se·ri·ous·ly, adverbul·tra·se·ri·ous·ness, nounun·se·ri·ous, adjectiveun·se·ri·ous·ly, adverbun·se·ri·ous·ness, noun

Synonyms for serious

2. sober, sedate, staid. 3. See earnest1. 5. momentous, grave.

Antonyms for serious

3, 5. trivial.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for half-serious

Contemporary Examples of half-serious

Historical Examples of half-serious

British Dictionary definitions for half-serious

half-serious

adjective

not entirely serious
Derived Formshalfseriously, adverb

serious

adjective

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
Derived Formsseriousness, noun

Word Origin for serious

C15: from Late Latin sēriōsus, from Latin sērius; probably related to Old English swǣr gloomy, Gothic swers esteemed
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for half-serious

serious

adj.

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.

Online Etymology Dictionary, © 2010 Douglas Harper
Medicine definitions for half-serious

serious

[sîr′ē-əs]

adj.

Being of such import as to cause anxiety, as of a physical condition.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.