flap (one's) gums
To chatter or blather. Quit flapping your gums—I need some quiet so I can think! Whenever Charlie starts to flap his gums, I can't get in a word!
flap one's gums
and flap one's jawsRur. to talk aimlessly. They're still out on the porch, flapping their gums. Well, I can't sit here flapping my jaws all day. Gotta get back to work.
flap your gums
AMERICAN, INFORMALIf someone flaps their gums, they talk a lot without saying anything important. Who wants to hear you flapping your gums first thing in the morning?