[ weer-doh ]
/ ˈwɪər doʊ /
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noun, plural weird·os.Informal.
an odd, eccentric, or unconventional person.
a psychopath, especially a dangerous or vicious one; psycho: They caught the weirdo who attacked the children.
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Origin of weirdo

First recorded in 1950–55; weird + -o
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does weirdo mean?

A weirdo is a person who behaves in ways that are considered odd or unconventional.

Weirdo is based on the adjective weird, which most commonly means strange, odd, peculiar, or bizarre. Weirdo is very informal. It can be used both negatively as an insult and positively as a compliment, depending on how you feel about someone else’s weird behavior.

Much less commonly, weirdo can be used as an informal term for a person considered a dangerous psychopath.

Example: My dog keeps licking the wall—what a weirdo!

Where does weirdo come from?

The first records of weirdo come from the 1950s. It’s a combination of the word weird and the suffix o, which is used to form nouns that refer to people who exhibit a certain quality, especially in a negative way, as in sicko and cheapo.

A weirdo is someone who does or says weird things. But there are shades of weirdo. Sometimes when we call people weirdos we’re trying to insult them or shame them for doing something we consider unacceptably bizarre, as in Some weirdo in my apartment keeps playing “Happy Birthday” at 3 a.m. But a weirdo might be a completely harmless eccentric—just someone who does things considered odd, like always eating pizza crust-first or naming their fingernails. Most people are a weirdo in at least some way—I mean, what kind of weirdo doesn’t do anything weird? If we value weirdness, then weirdo becomes a term of fondness and affection, and we seek out other wonderful weirdos to be weird with.

Weirdo is formed from the adjective weird but it is sometimes used as an adjective itself, as in Do you hear yourself when you suggest these weirdo ideas? It means about the same thing as weird, but it has all the same potential implications of the word weirdo when it’s used as a noun—meaning it can be positive or negative depending on the intent of the speaker.

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How is weirdo used in real life?

Weirdo is very informal. It’s used both positively and negatively depending on what the speaker wants to imply about the person they’re calling a weirdo.


Try using weirdo!

Is weirdo used correctly in the following sentence? 

That guy talks really weirdo.

How to use weirdo in a sentence

British Dictionary definitions for weirdo


weirdie (ˈwɪədɪ)

/ (ˈwɪədəʊ) /

noun plural -dos or -dies
informal a person who behaves in a bizarre or eccentric manner
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012