Anatomy, Zoology .

the opening through which an animal or human takes in food.

the cavity containing the structures used in mastication.

the structures enclosing or being within this cavity, considered as a whole.

the masticating and tasting apparatus.

a person or animal dependent on someone for sustenance

another mouth to feed.

the oral opening or cavity considered as the source of vocal utterance.

utterance or expression

to give mouth to one's thoughts.

talk, esp. loud, empty, or boastful talk

That man is all mouth.

disrespectful talk or language; back talk; impudence.

a grimace made with the lips.

an opening leading out of or into any cavity or hollow place or thing

the mouth of a cave; a bottle's mouth.

the outfall at the lower end of a river or stream, where flowing water is discharged, as into a lake, sea, or ocean

the mouth of the Nile.

the opening between the jaws of a vise or the like.

the lateral hole of an organ pipe.

the lateral blowhole of a flute.

to utter in a sonorous or pompous manner, or with excessive mouth movements

to mouth a speech.

to form (a word, sound, etc.) with the lips without actually making an utterance

She silently mouthed her answer so as not to wake her napping child.

to utter or pronounce softly and indistinctly; mumble

Stop mouthing your words and speak up.

to put or take into the mouth, as food.

to press, rub, or chew at with the mouth or lips

The dog mouthed the toys.

to accustom (a horse) to the use of the bit and bridle.

to speak sonorously and oratorically, or with excessive mouth movement.

to grimace with the lips. ?

mouth off, Slang .

to talk back; sass

He mouthed off to his mother.

to express one's opinions, objections, or the like in a forceful or uninhibited manner, esp. in public. ?

down in or at the mouth

Informal . dejected; depressed; disheartened

Ever since he lost his job, he has been looking very down in the mouth.

run off at the mouth

Informal . to talk incessantly or indiscreetly.

talk out of both sides of one's mouth

to make contradictory or untruthful statements.

noun

aperture , beak , box , cavity , chops , clam , crevice , delta , door , embouchement , entrance , estuary , firth , fly trap , funnel , gate , gills , gob , harbor , inlet , jaws , kisser , lips , mush * , orifice , portal , rim , trap * , yap * , boasting , braggadocio , bragging , cheek , empty talk * , freshness , gas * , guff * , hot air * , idle talk , impudence , insolence , lip * , rudeness , sass * , sauce * , gob* , puss* , trap* , grimace , moue , pout , spokesman , spokesperson , spokeswoman , opening , outlet , vent , crow , gab , mug , os , stoma , voice

verb

declaim , harangue , perorate , rave , mug