Originally Posted by DataJunkie
/\ LOL!
What the heck is a mouth-breather?
How can one not be a mouth breather? Only breathe using your nose?
That saying is puzzling. I must be getting old
Medically, you are correct. However:
mouth-breather. n. "a stupid person; a moron, dolt, imbecile." English Pejorative Slang.
The original definition of "mouth-breather" referred to a person that, due to medical problems (usually with the sinuses or nose), was forced to breathe via the mouth. This leaves the jaw hanging open at most times, which has a tendency to make a person look "dopey" or "spacey".