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mouthbreather also mouth-breather or mouth breather

noun [countable] mainly American offensive

a stupid person


adjective mainly American offensive


'These mouthbreathers cannot offer any new ideas, so instead of trying to compete with conservatives, they're busy with the electronic equivalent of sticking their fingers into their ears and shouting, "LA-LA-LA-LA, NO ONE CAN HEAR YOU!!" as loudly as possible.'

The Jawa Report 23rd January 2006

'Please listen closely, as we believe you are a mouthbreathing idiot who would be lucky to remember how to find your way back to the house from the mailbox if you didn't leave yourself a trail of breadcrumbs.'

Mister Green 29th April 2006

From berk to blockhead, dimwit to dork and plonker to prat, over the centuries the English language has never been short of ways of referring to a stupid person. In fact, there's practically one word with this definition for every letter of the alphabet, and if you don't believe me, consider: ass, birdbrain, chump, dipstick, fool, goon, half-wit, imbecile, jerk, knucklehead, lemon, moron, nincompoop, oaf, plonker, schmuck, twit and wally, to name but a few. Potentially joining the ranks at the letter 'm' is mouthbreather, a term which is rapidly gaining currency in the popular media, as the citations above illustrate.

someone who breathes though their mouth often has their jaw hanging open, which has a tendency to make them look rather vacant or stupid

Mouthbreather, yet another pejorative term for describing a stupid person, also occurs as both an open and hyphenated compound. There is also some evidence for it having morphed into an adjective mouthbreathing. Essentially a metaphorical expression, it is based on the idea that someone who breathes though their mouth often has their jaw hanging open, which has a tendency to make them look rather vacant or stupid. Like many new words, its popular use has been propagated on the Web, particularly by bloggers (writers of weblogs), as the two citations above demonstrate.

Background – mouthbreather

The original definition of the word mouthbreather, is simply someone who habitually breathes though their mouth, rather than through their nose. In medical contexts, the term contrasts with nose breather, a person who breathes only through their nose, rather than through their mouth (babies and infants are nose breathers). Mouthbreathers are people that are forced to breathe through their mouth due to medical problems associated with the sinuses or nose. They can suffer from chronic snoring and sleep apnea, (a condition whereby someone can essentially suffocate during the night due to a breathing lapse).

The use of the word as an insult, based on the idea of the dopey expression of someone with their jaw hanging open, and possibly the nasal sound of their voice, actually dates as far back as the 1940s, but has recently emerged from obscurity through use on the Web, especially in the US, where it has also been used on television and by the popular press.

by Kerry Maxwell, author of Brave New Words

This article was first published on 29th May 2006.

Open Dictionary

Dunning-Kruger effect

the phenomenon by which an incompetent person is too incompetent to understand his own incompetence

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