What does serious mean?
Serious is an adjective describing things that are important, grave, or deserving of careful attention. Its most common use refers to a significant matter, problem, or concern, as in 'a serious issue.' It can also describe a person who is sincere, thoughtful, and intent on doing something properly. In another established sense, serious means solemn rather than humorous: a serious expression or a serious conversation signals gravity and purpose. Context also gives it the sense of severity, so a serious injury or serious danger is far more consequential than a minor one. These related meanings share an emphasis on weight and significance rather than lightness or triviality. The word is useful because it captures both the practical importance of a situation and the emotional gravity of a person's manner. Its standard related forms are 'seriously' and 'seriousness,' which allow the adjective's sense of importance or gravity to be expressed as an adverb or noun.
adjectiveImportant enough to deserve attention or careful treatment; not trivial, playful, or joking. It can also describe a solemn or earnest manner, a severe situation, or a sincere and dependable person.
- Important, significant, or deserving of attention.
- Solemn or earnest in manner, without humour or flippancy.
- Severe, dangerous, or capable of having serious consequences.
- Sincere, thoughtful, and dependable in purpose or character.
"The proposal raised a serious concern about the privacy of the company's users."
"Climate change remains a serious threat to coastal communities."
"Her quiet, serious manner made people assume she was upset."
The Latin word behind serious meant 'earnest' or 'grave,' but its own origin is still a mystery.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does serious come from?
English borrowed serious from Latin serius, a word meaning 'earnest,' 'honest,' or 'grave.' Over time, its use broadened from describing a person's manner or attitude to describing matters of importance and gravity. The origin of the Latin word itself is uncertain, so its exact relationship to other Romance and Latin words cannot be stated with confidence.
Related word forms
How serious is actually used
The standard adverb is 'seriously.' Using 'serious' informally as an intensifier, as in 'serious trouble,' is established in casual speech but can sound emphatic or slightly nonstandard.