口にものをほおばってしゃべるな。

mouth; opening; hole; gap; orifice; mouth (of a bottle); spout; nozzle; mouthpiece; gate; door; entrance; exit; speaking; speech; talk (i.e. gossip); taste; palate; mouth (to feed); opening (i.e. vacancy); available position; invitation; summons; kind; sort; type; opening (i.e. beginning); counter for mouthfuls, shares (of money), and swords

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

person

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to stuff one's cheeks; to fill one's mouth (with food)

to talk; to chat; to chatter

(sentence end, mainly masc.) indicates emotion or emphasis; (used with masu stem verb) command; (used with dictionary form verb) prohibition