What does birdbrained mean?
Birdbrained is an informal adjective meaning foolish, silly, or lacking good sense. It comes from the noun birdbrain, which reflects the old assumption that a bird's small brain equates to low intelligence — an assumption modern science has thoroughly undermined, since crows, ravens, and parrots display remarkable problem-solving abilities. In contemporary use, calling a person birdbrained suggests they are scatterbrained or thoughtless rather than deeply unintelligent, and applying it to a plan or idea signals that it is impractical or poorly conceived. The word carries a teasing, dismissive tone that is milder than outright insults, making it a favourite in casual conversation and light criticism. It is well established in both British and American English, though it remains firmly colloquial.
adjectiveFoolish or silly; lacking intelligence or common sense. The term derives from the notion that a bird's brain is tiny and incapable of complex thought.
- (of a person or their ideas) foolish, silly, or showing poor judgement; lacking common sense.
"It was a birdbrained plan to cross the desert without extra water."
"Only someone truly birdbrained would leave the front door wide open all night."
"The committee rejected his birdbrained proposal to fund the office party with the safety budget."
Calling someone 'birdbrained' is arguably unfair to birds — crows and parrots routinely outperform many mammals on intelligence tests.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of birdbrained
Birdbrained is formed from the compound birdbrain, itself a straightforward combination of bird and brain that arose in English as a term of contempt for a stupid person, attested from around the early twentieth century. The adjective simply adds the suffix -ed, following the pattern of compounds such as pigheaded and lighthearted. Its underlying logic draws on the longstanding folk belief that small brains imply simple minds; while scientifically dubious for many bird species, this association gave the word its lasting figurative force. There are no foreign cognates — the word is a native English formation built from Germanic roots shared with the ordinary words bird and brain.
Related word forms
How birdbrained is actually used
Informal and mildly derogatory; used in everyday speech rather than formal writing. It can apply to people, plans, or ideas, and is generally lighter in tone than harsher insults like 'stupid' or 'idiotic.'
Easily confused with birdbrained
Birdbrain is the noun referring to a foolish person, while birdbrained is the adjective describing something or someone as foolish.