What does boob mean?
'Boob' is an informal noun that carries two distinct meanings in modern English. Its older and more traditional sense denotes a stupid, clumsy, or gullible person — a fool — a usage inherited from the longer word 'booby'. In this sense it appears in phrases like 'don't be a boob', conveying mild, often affectionate mockery rather than serious insult. Since the mid-twentieth century, particularly in American English, the word has also developed a slang sense referring to a woman's breast, a usage that is considered vulgar and inappropriate in formal contexts. The word's two meanings coexist today, though the anatomical sense now dominates popular awareness, helped along by expressions like 'boob tube' (a slang term for television) and 'boob job' (colloquial slang for breast augmentation surgery). Because of its casual register and potentially offensive connotation, writers should use 'boob' only in light-hearted or deliberately colloquial contexts, never in formal or professional prose.
A stupid, clumsy, or foolish person.
"I felt like a total boob when I realised I'd been reading the map upside down."
Informal and mildly derogatory; often used playfully rather than harshly.
(Slang) A woman's breast.
"The comedian's joke about her dress drew more attention than the punchline itself."
Vulgar or indelicate slang, chiefly North American; avoid in formal contexts.
The plural applies to both senses: 'boobs' for multiple fools, and as the standard way to refer to breasts in slang.
"The sitcom was full of boobs and buffoons, none of them remotely clever."
'Boob' meaning 'a fool' is actually the older sense — the anatomical slang didn't appear until the mid-20th century, so for centuries calling someone a boob was an insult to their brain, not a reference to their body.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of boob
'Boob' derives as a shortened form of 'booby', a word attested from the late sixteenth century meaning a fool or simpleton. 'Booby' itself most likely comes from Spanish 'bobo', meaning stupid or dull, which traces back through Latin 'balbus', meaning stammering or lisping. The anatomical slang sense of 'boob' emerged much later, in American English around the mid-twentieth century. A related coinage is 'booboisie', a blend coined by the American critic H. L. Mencken to satirise the unthinking masses.
Related word forms
How boob is actually used
Both senses are informal and mildly colloquial. The 'fool' sense is old-fashioned in British English but still current in American English. The breast sense is slang and considered vulgar or at least indelicate in polite conversation; it should be avoided in formal writing.
Easily confused with boob
A booby is a foolish person or a seabird, whereas a boob is the informal short form for such a person or slang for a breast.