mouth-breather
I’m more than ready to take on the mouth-breathing thugs.
He's a basement-dwelling, mouth-breathing troll.
They've spent whole careers playing mouth-breathing, monosyllabic, and violent men.

SMART Vocabulary: related words and phrases

Stupid and silly
absurd
absurdity
absurdly
adolescent
against your better judgmentidiom
dopey
dopily
dorky
dottiness
dotty
imprudently
in his/her/their wisdomidiom
in someone's infinite wisdomidiom
inadvisable
injudicious
uncritical
uncritically
undiscriminating
unintelligent
unperceptive

Examples of mouth-breathing

mouth-breathing
To attempt to stop mouth-breathing before providing abundant air-space through the nostrils is not only irrational, but cruel.
From Project Gutenberg
A mouth-breathing child is very apt to catch cold and as a consequence of the habit may become catarrhal or tubercular.
From Project Gutenberg
The most common reason for mouth-breathing is the growth of small lumps in the throat just behind the nose.
From Project Gutenberg
The harmfulness of mouth-breathing is explained in another chapter.
From Project Gutenberg
Nevertheless, mouth-breathing in all ages has been regarded as a bad habit, and with good reason.
From Project Gutenberg
Many of the diseases to which civilized man is subject are undoubtedly caused by this common habit of mouth-breathing.
From Project Gutenberg
Among diseases predisposing to consumption, ordinary colds and bronchitis, influenza, pneumonia, measles, nasal obstruction causing mouth-breathing, and scarlet fever are the most important.
From Project Gutenberg
If he persists in this, closes the mouth when he goes to sleep, in time the mouth-breathing will cease, and with it the disagreeable habit of snoring.
From Project Gutenberg
The collapsed state of the wings of the nose, and wasted condition of their muscles, resulting from long disease, often contributes to the perpetuation of the mouth-breathing habit.
From Project Gutenberg
We are unable to see adenoids because of their position, but can be reasonably sure of their presence in children where we find symptoms resulting from mouth-breathing as described below.
From Project Gutenberg
Many persons who, for the sake of appearances, keep their mouth closed during the day, persist in mouth-breathing at night and often contract disease in this way.
From Project Gutenberg
Many contagious diseases are contracted by the disgusting habit of mouth-breathing, and many cases of cold and catarrhal affections are also attributable to the same cause.
From Project Gutenberg
Mouth-breathing is not simply a bad habit, a careless trick on the part of the child.
From Project Gutenberg
These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors.