Definition of black-mouthed in US English:

black-mouthed

adjective

  • Having a black mouth; (figurative) slanderous; foul-mouthed.

Origin

Mid 16th century; earliest use found in John Heywood (c1496–c1578), playwright and epigrammatist. From black + mouthed. In black-mouthed dogfish after scientific Latin melanostomus.

Pronunciation

black-mouthed

/ˈblakˌmaʊðd/