[ˈluːni], (Noun)

Definitions:
- an extremely irrational, eccentric, or foolish person
(e.g: she was working with a bunch of loonies)

- a person who has a mental illness


Phrases:

Origin:
mid 19th century: abbreviation of lunatic

[ˈluːni], (Adjective)

Definitions:
- very irrational, unrealistic, or impractical
(e.g: it was pretty amusing to check out some of the more loony responses)

- having a mental illness


Phrases:

Origin:
mid 19th century: abbreviation of lunatic