What does loony mean?
Loony is an informal word for describing someone or something crazy, eccentric, or absurd. Its tone can range from gently teasing to openly derogatory, depending on the speaker and the situation: calling a comic performance “loony” may be a compliment, while describing dangerous conduct as “loony” usually expresses disapproval. The word is especially common in North American English, though it is also understood in British English. It can also function as a noun for a person regarded as eccentric or foolish. In informal writing and conversation, loony is often more playful than the more formal “crazy,” “insane,” or “lunatic,” but it remains unsuitable for precise or sensitive discussion of mental health.
Informally crazy, eccentric, or absurd; also, in a playful sense, wildly enthusiastic.
"That was a loony but memorable idea."
Informal and sometimes derogatory; common especially in North American English.
A person regarded as crazy, eccentric, or foolish.
"The old man seemed like a loony to his neighbours."
Informal and usually mildly derogatory; more common in North American English.
The plural is uncommon but standard in informal usage.
"The film follows two loonies who accidentally uncover a government conspiracy."
Loony began as a label for a “lunatic,” but today it can be used affectionately to describe anything delightfully ridiculous.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does loony come from?
The word developed in the 19th century from the older informal word “loon,” which had been used for a person regarded as foolish or insane. The ultimate connection is with the Latin root underlying “lunatic,” relating originally to the moon and later to ideas of frenzy or abnormality. The later sense of “extremely enthusiastic” developed in the 20th century and is often playful rather than insulting.
Related word forms
How loony is actually used
Loony is informal and usually somewhat dismissive, though it can be playful or admiring depending on context. It is especially common in North American English and should generally be avoided in formal or highly sensitive contexts.
Easily confused with loony
A loon is a person considered strange or foolish, while loony is usually an adjective describing someone or something as crazy, eccentric, or absurd.
Lunatic is more formal and often carries a stronger implication of insanity, whereas loony is generally informal and may be playful rather than seriously derogatory.