(idiomatic, mildly insulting) One lacks good taste in aesthetic or cultural matters.

plural of mouth bar

(geomorphology) A bar that forms in the middle of an estuary or of a channel in a river delta.

(obsolete) A blustering, boisterous person. / (obsolete, acting) An overactor.

(obsolete) Vociferous.

(poetic) Having a low-pitched voice.

(idiomatic) To deprive someone of the means of living.

Used other than figuratively or idiomatically: see plum, in, mouth. / A plummy British accent.

(derogatory, vulgar) foolish talkativeness, logorrhea

(often imperative) To watch one's mouth, especially regarding swear words.