# loony

/ˈɫuni/ (US) · /lˈuːni/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/loony
Updated: 2026-05-26

## Definition

a person who is considered to be mentally unbalanced or acting in a very strange way. It is a very informal and slightly rude word for someone who is acting crazy.

For teachers: a person perceived as mentally unstable or behaving in an irrational, eccentric, or foolish manner. Highly informal and often considered vulgar or derogatory depending on the context.

## Examples

- He is such a loony for thinking he can fly.
- The crowd laughed at the loony who was wearing a full suit of armor in the middle of the street.
- While some critics dismissed the director as a loony eccentric, his latest film has actually been hailed as a masterpiece of modern cinema.

---

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.