mouth vs open up

Other hyponyms of mouth include read, phonate, vocalise, vocalize, troll, begin, lip off, shoot one's mouth off, shout, whisper, peep, speak up, snap, snarl, enthuse, speak in tongues, swallow, verbalise, verbalize, whiff, talk about, talk of, blubber, blubber out, drone, drone on, bumble, falter, stammer, stutter, rasp, blunder, blunder out, blurt, blurt out, ejaculate, inflect, modulate, tone, deliver, present, generalise, generalize, blab, blabber, chatter, clack, gabble, gibber, maunder, palaver, piffle, prate, prattle, tattle, tittle-tattle, twaddle, chatter, jaw, rattle on, yack, yack away, yap away, snivel, whine, murmur, maunder, mumble, mussitate, mutter, slur, bark, bay, jabber, mouth off, rabbit on, rant, rave, spout, hiss, sibilate, siss, sizz, cackle, babble, chant, intone, tone, gulp, sing, talmbout.