run off at the mouth

1. Talk incessantly, babble, as in Wilbur is always running off at the mouth about his investments. This idiom transfers a flow of water to an unending flow of words. [Slang; c. 1900]

Example Sentences

And we can also be fairly certain that both athletes will continue to run off at the mouth before they run on the track.

From Los Angeles Times

If Carlson insisted on it, it may be because he wants to control it instead of letting Trump run off at the mouth as he does in live interviews.

From Salon

In 19 N.B.A. seasons as the strong, silent and never-salacious type, Duncan did not write a book, run off at the mouth, or elaborate on much.

From New York Times

Even with methodical training they were inclined to run off at the mouth, make unnecessary displays of themselves, unconsciously slip in the tiniest flourish that could scare off a nervous contact.

From Literature

Out in Marlboro country before the turn of the century, Harvardmen don't amount to much�they are apt to sing and dance and run off at the mouth.

From Time Magazine Archive

Related Words

• blubber 
• burble 
• mumble 
• murmur 
• mutter