- A person who behaves as if they know everything.
- They often offer unsolicited advice, correct others frequently (sometimes wrongly), and act superior due to their perceived knowledge.
Explanation
Origin
- A straightforward compound noun: someone who claims or acts like they know it all.
- The term has been in common usage since at least the early 20th century.
Synonyms & Related Expressions
Alternatives
Slang/Informal:
- Smart aleck / Wise guy / Wiseass / Smartass (Often implies sarcasm or showing off intelligence rudely)
- Smarty-pants (Can sound childish or teasing)
- Bighead / Swelled head (Focuses on arrogance/ego related to intelligence)
- Armchair expert / Armchair quarterback (Someone offering expert opinions without real experience)
- Pedant (Focuses on someone overly concerned with minor details or rules)
- Mr./Ms. Know-it-all (Common variation)
Vulgar/Emphatic:
- Fucking know-it-all (Vulgar intensifier)
- Smart arse / Smart ass (Common, vulgar)
Milder/More Formal:
- Opinionated (Holds strong opinions, perhaps inflexibly)
- Dogmatic (Asserts opinions as undeniable truths)
- Pedantic (Overly concerned with formalism and precision)
- Condescending / Patronizing (Talks down to others)
- Overbearing (Tries to impose their views)
- Didactic (Inclined to teach or lecture others, often unwantedly)
Situational Appropriateness
- Informal. It's a direct insult.
- While the underlying behavior (being condescending, overly opinionated) might be discussed in professional settings, using this label is usually reserved for informal complaints or gossip.
Misunderstanding Warnings
- The negative connotation is strong and clear. It's never a compliment.
Examples
- He's such a know-it-all; you can't tell him anything without him claiming he already knew it or knows better.
- During the presentation, she kept interrupting with 'Well, actually...' – total know-it-all behavior.
- I try to avoid discussing politics with him because he turns into a condescending know-it-all.
Dialogue
Sam: I mentioned I was thinking of trying meditation.
Alex: Oh no, what did Brenda say? Let me guess, she gave you a 20-minute lecture on the history and proper techniques?
Sam: Exactly! She's such a know-it-all. I just wanted to mention it, not get certified.
Alex: (Sighs) Classic Brenda.
Social Media Examples
- Tweet: The worst part of online forums? The inevitable know-it-all who jumps into every thread to correct minor details. #internetlife
- Rant post: Dealing with a know-it-all sibling during family gatherings requires the patience of a saint. 😤
- Comment: Dude, nobody likes a know-it-all. Just let people have their opinions.
Response Patterns
- Strong agreement: Tell me about it!, Drives me crazy!, Absolutely unbearable.
- Sharing frustrating experiences: I know! The other day he tried to tell me how to do my job.
- Expressing annoyance: Ugh, I can't stand people like that.
Common Follow-up Questions/Actions
After calling someone a know-it-all:
- People often vent by recounting specific irritating instances: You won't believe what he said...
- Discussion might turn to how annoying or counterproductive the behavior is.
- People might resolve to avoid engaging the person in discussions where they exhibit this trait.
Conversation Starter
- No. Describes an annoying personality trait observed in someone.
Intonation
- Usually spoken with annoyance, irritation, or exasperation.
- Stress is typically strong and somewhat equal on know, it, and all.
- a KNOW-IT-ALL.
Generation Differences
- Universally understood and used across all generations.
Regional Variations
- Common everywhere in the English-speaking world.
- Smart arse (UK/Aus/NZ) or Smart ass (US/Canada) conveys a similar idea, often focusing more on sarcastic or insolent displays of supposed intelligence.