# lighten up

CEFR B2 · Phrasal verb

Source: https://englishreference.com/word/lighten-up
Updated: 2026-10-22

## Definition

to stop being so serious or worried and start being more relaxed. You use this when someone is taking a situation too seriously or getting angry about a small problem.

For teachers: to adopt a less serious, formal, or somber attitude. The verb is primarily used intransitively in this idiomatic sense to encourage a change in mood or perspective.

## Examples

- Lighten up, it was only a joke!
- After working for twelve hours straight, Sarah told her boss he needed to lighten up and go home to his family.
- The tension within the diplomatic envoy began to dissipate only when the lead negotiator finally decided to lighten up and share a personal anecdote.

## Pitfalls

- Not "He lightened up a cigarette before the meeting." but "He lit up a cigarette before the meeting." — Learners often confuse the verb 'lighten' (to make less heavy or serious) with the verb 'light' (to ignite).

## Usage notes

- This phrase is most commonly used in the imperative mood as a command or a piece of friendly advice.
- Teaching tip: Contrast this with 'calm down'; while 'calm down' addresses high energy or anger, 'lighten up' specifically targets excessive seriousness or a gloomy mood.

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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.