What it means
A know-it-all is the one who always has the answer, has read the article, has been there already and will happily correct you mid-sentence whether you asked or not. It's the smug certainty that grates, the need to top every story and win every fact. Tiring company, even when they happen to be right, which annoyingly they often are.
Usage examples
"Nobody wants the know-it-all on quiz night correcting the host's answers."
"He's such a know-it-all, he finished my sentence and then told me I was wrong."
Where it comes from
A plain run-together of know it all, the person who acts as if they know everything. It's labelled the insufferable expert since the 1800s.
Editors of this term
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