an extremely irrational, eccentric, or foolish person
she was working with a bunch of loonies
only a few wild-eyed loonies are claiming that it was part of some deliberate scheme
a person who has a mental illness
very irrational, unrealistic, or impractical
it was pretty amusing to check out some of the more loony responses
some are even dumb enough to post all their loony thoughts and plans on a public social media platform
having a mental illness