Crackbrain

Part of speech: noun

Definitions

1. A person who is mad, unhinged or extremely foolish ; a plan or scheme that seems wildly unsound or impractical
2. Someone regarded as mentally unstable or absurdly reckless ; a notion, project or idea considered crazy, senseless or unworkable
3. A crazy or unbalanced individual ; describing an impractical or absurd idea, scheme or undertaking that makes little sense

Etymology: "Crackbrain" is a plain compound of "crack" and "brain," with the "crack" here used in its older sense of something flawed or unsound, as in a cracked bell or cracked vessel. Put together, the pair describes a mind that has a fault running through it, much as a cracked pot leaks. The noun names a person considered crazy or eccentric in a foolish way. The image is a familiar one in English, since "cracked" was used for a damaged or unhinged mind long before "crackbrain" appeared as a compound. The word was formed by joining the two plain English nouns and needs no borrowed or classical roots to explain it.

Synonyms: lunatic, madman, nutcase, maniac, crackpot

Antonyms: sage