A person who routinely inhales and exhales through the mouth, instead of through the nose. / (idiomatic, slang, derogatory) A person who is boorish, stupid, or otherwise unattractive.

Alternative spelling of motormouth

prone to speaking evasively, indirectly, or duplicitously; not forthright

The vocal imitation of instrumental music. / Words (or sometimes actions) that sound good but do not mean anything.

(idiomatic) The mouth of someone who talks too much, especially by making exaggerated claims or by inappropriately revealing information.

(idiomatic) Verbal means of passing on information.

(medicine) Abnormal dryness of the mouth

Alternative spelling of badmouth

present participle of bad-mouth

simple past tense and past participle of bad-mouth