boob

UK: /ˈbuːb/ US: /bub/ ,(bo̅o̅b)

WordReference Random House Learner's Dictionary of American English © 2026

boob¹ /bub/   [Slang.]
n. [countable]

1. Slang Terms a fool or stupid person.

v. [no object]
2. Slang Terms, British Terms Brit. to blunder:
   He boobed again and failed that test.

boob² /bub/   n. [countable] Slang (sometimes vulgar).

1. Slang Terms a female breast.

WordReference Random House Unabridged Dictionary of American English © 2026

boob¹  (bo̅o̅b), [Slang.]
n. 

1. Slang Terms a stupid person;
   fool;
   dunce.
2. Slang Terms, British Terms [Brit.] a blunder;
   mistake.

v.i. 

3. Slang Terms, British Terms [Brit.] to blunder.

• back formation from booby¹ 1905–10, American.

boob²  (bo̅o̅b), n. [Slang] (sometimes vulgar).

1. Slang Terms a female breast.

• apparently back formation from booby² 1945–50

Collins Concise English Dictionary © HarperCollins Publishers::

boob / buːb/ noun

1. an ignorant or foolish person; booby
2. an embarrassing mistake; blunder
3. a female breast

verb

1. (intransitive) to make a blunder

Etymology: 20th Century: back formation from booby