Failed a test, class, or other examination; did not achieve a passing grade.
From American slang 'flunk', possibly from Germanic 'flank' or related to 'funk' (to avoid). It became popular in American schools in the 1800s.
Flunk is pure American student slang that's so common we forget it's relatively recent—the British say 'failed' while Americans 'flunked.' The word captures the shame of failing better than any formal term could.
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