English Reference

Word

boob

US/ˈbub/

UK/bˈuːb/

Definitions

01a breast

B2 · Upper Intermediate Countable noun Informal · Slang · Vulgar

n. a slang word for a woman's breast.

n. a slang term for the female breast. Informal and often considered vulgar in professional contexts.

“She felt uncomfortable when the men at the bar made a joke about her boobs.”

“The tabloid was criticised for its focus on the actress's physical appearance, specifically for publishing invasive photos of her boobs while she was on holiday.”

Teaching tip

While common in casual speech among friends, this term is vulgar and should be avoided in any formal, academic, or professional setting.

Synonyms

02a mistake

B2 · Upper Intermediate Countable noun British English · Informal

n. a silly or embarrassing mistake.

n. an informal term for a blunder or error. Primarily used in British English.

“I made a bit of a boob by sending the email to the wrong person.”

“The presenter made a massive boob during the live broadcast by mispronouncing the prime minister's name.”

Usage

Often used in the phrase 'to make a boob'.

03a foolish person

C1 · Advanced Countable noun American English · Informal · Archaic

n. a person who is silly or not very smart.

n. a person regarded as stupid or foolish. This sense is somewhat dated in modern American English.

“Don't be such a boob; everyone knows that's not how the machine works.”

“The protagonist was portrayed as a well-meaning boob who constantly stumbled into success despite his lack of intelligence.”

Synonyms

foolidiotnitwit

04to make a mistake

C1 · Advanced British English · Informal

v. to make a silly error.

v. to commit a blunder or mistake. Intransitive use, primarily British.

“The goalkeeper really boobed when he let that easy ball roll into the net.”

“The administration admitted they had boobed significantly regarding the new tax policy implementation.”

Synonyms

errslip upblunder

Etymology

Clipped form of booby (“fool”). Appeared near the beginning of the twentieth century; more information at booby § Etymology 1.

Clipped form of booby (“breast”). Appeared from the 20th century; more information at booby § Etymology 2.

Apparently shortened from booby-hatch.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B1 PreliminaryIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.4.0–5.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 3.0–3.544–71TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.550–784
Frequency
Frequent
Level
B1 · Intermediate
Updated

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English Reference