# serious

/ˈsɪɹiəs/ (US) · /sˈiəɹɪəs/ (UK)

Source: https://englishreference.com/word/serious
Updated: 2026-06-19

## Senses

### 1. not joking or funny

adjective · CEFR A2

quiet and thinking carefully, without laughing or making jokes.

For teachers: characterized by a grave or somber disposition; lacking humor or levity in manner.

- The teacher looked very serious when he told the students to be quiet.
- The lead investigator maintained a serious expression throughout the briefing, refusing to indulge in the lighthearted banter of his colleagues.

### 2. important or dangerous

adjective · CEFR A2

important and needing a lot of thought because it could cause problems.

For teachers: having significant or dangerous consequences; not trivial or slight.

- The doctor said it was a serious injury and she needed to stay in the hospital.
- The board of directors met to discuss the serious financial implications of the failed merger, acknowledging that the company's future was at stake.

### 3. sincere and honest

adjective · CEFR B1

really meaning what you say and not just pretending or playing.

For teachers: acting in earnest; sincerely intending to carry out a stated plan or promise.

- Are you serious about moving to another country for work?
- Despite his reputation for sarcasm, he was entirely serious when he offered to fund the local community project.

### 4. very committed

adjective · CEFR B1

giving a lot of time and energy to an activity because you care about it.

For teachers: deeply interested in or devoted to a particular activity or subject.

- She is a serious student who spends every weekend in the library.
- As a serious collector of rare manuscripts, he spent decades scouring European auctions to complete his primary research library.

### 5. seriously

adverb · CEFR C1 · Informal · Dialect

used in some phrases to mean 'in a serious way'.

For teachers: functioning as an adverbial modifier, particularly in fixed collocations like 'take serious' or 'mean serious'.

- You shouldn't take him too serious when he is in a bad mood.
- The foreman warned the crew that the safety inspector would take any violations serious, regardless of past performance.

Usage: In standard English, 'seriously' is required; this form is restricted to specific informal or regional speech patterns.

## Examples

- We need to have a serious talk about your future.
- The doctor said the injury is serious and requires immediate surgery to prevent further damage.
- While the initial reports were dismissed as rumors, the government eventually issued a serious warning regarding the economic stability of the region.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.