loony

adj, noun — 3 senses

loony

adj

/ˈluːni/

Etymology Shortened from lunatic, and likely also from loon ("rascal", and also the bird) + -y.

1

Derogatory, Informal, Offensive, Of a person Insane.

loony scheme
completely loony

2 more examples

They dismissed his loony ideas.
The movie is full of loony characters.

2

Derogatory, Informal, Offensive, Of a thing Very silly, absurd.

Derived terms: loonily, looniness, loony bin, loony dooker, loony left, loony lefty, loonytarian, loonytarianism, loony toon, loony tune, loony tunes, loony van, Maniloony
Related terms: lunacy

loony

noun

Etymology Shortened from lunatic, and likely also from loon ("rascal", and also the bird) + -y.

1

Derogatory, Informal, Offensive An insane or very foolish person.

Why, there’s hundreds of lunies of the sort to be met in London.1913, Marie Adelaide Belloc Lowndes, The Lodger:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.