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mouth (mouth)
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n.pl. mouths(mouthz)
1.
a. The body opening through which an animal takes in food.
b. The cavity lying at the upper end of the digestive tract, bounded on the outside by the lips and inside by the oropharynx and containing in humans and certain other vertebrates the tongue, gums, and teeth.
c. This cavity regarded as the source of sounds and speech.
d. The opening to any cavity or canal in an organ or a bodily part.
2.
a. The part of the lips visible on the human face.
b. A pout, grimace, or similar expression:made a mouth when the teacher turned away.
3.
a. A person viewed as a consumer of food:has three mouths to feed at home.
b. A spokesperson; a mouthpiece:acts as the mouth of the organization.
4.
a. Utterance; voice:gave mouth to her doubts.
b. A tendency to talk excessively or unwisely:is known mainly for his mouth.
c. Impudent or vulgar talk:Watch your mouth.
5. An opening, especially:
a. The part of a stream or river that empties into a larger body of water.
b. The entrance to a harbor, canyon, valley, or cave.
c. The opening through which a container is filled or emptied.
d. The muzzle of a gun.
e. The opening between the jaws of a vise or other holding or gripping tool.
f. An opening in the pipe of an organ.
g. The opening in the mouthpiece of a flute across which the player blows.
v.(mouth)mouthed, mouth·ing, mouths
v.tr.
1. To speak or pronounce, especially:
a. To declare in a pompous manner; declaim:mouthing his opinions of the candidates.
b. To utter without conviction or understanding:mouthing empty compliments.
c. To form soundlessly:I mouthed the words as the others sang.
2. To take in or touch with the mouth:Small children tend to mouth their toys.
v.intr.
1. To orate affectedly; declaim.
2. To grimace.
Phrasal Verb:
mouth offSlang
1. To express one's opinions or complaints in a loud, indiscreet manner.
2. To speak impudently; talk back.
Idiom:
down in/atthe mouth
Discouraged; sad; dejected.

[Middle English, fromOld Englishmūth; see men-2 in the Appendix of Indo-European roots.]
(click for a larger image)
mouth
the human mouth and its contiguous structures
A. hard palate
B. lips
C. teeth
D. salivary glands
E. trachea
F. esophagus
G. soft palate
H. tongue

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2016 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 

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