The Collaborative International Dictionary of English v.0.48:

Mouth \Mouth\ (mou[th]), v. t. [imp. & p. p. Mouthed
   (mou[th]d); p. pr. & vb. n. Mouthing.]
   1. To take into the mouth; to seize or grind with the mouth
      or teeth; to chew; to devour. --Dryden.
      [1913 Webster]

   2. To utter with a voice affectedly big or swelling; to speak
      in a strained or unnaturally sonorous manner; as, mouthing
      platitudes. "Mouthing big phrases." --Hare.
      [1913 Webster]

            Mouthing out his hollow oes and aes.  --Tennyson.
      [1913 Webster]

   3. To form or cleanse with the mouth; to lick, as a bear her
      cub. --Sir T. Browne.
      [1913 Webster]

   4. To make mouths at. [R.] --R. Blair.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "mouthing":
   Pecksniffery, Tartuffery, Tartuffism, cant, drone, droning,
   empty gesture, face, false piety, gabble, gibber, gibbering,
   grimace, hypocrisy, hypocriticalness, jabber, jibber, lip service,
   maundering, mealymouthedness, moue, mouth, mow, mug, mumble,
   mumbling, mummery, murmuring, mutter, muttering, oiliness,
   ostentatious devotion, pharisaism, religiosity, sanctimoniousness,
   sanctimony, snuffling, soft soap, susurration, sweet talk,
   tokenism, unctuousness, whisper, whispering