そしてついに口を開いた。

and; and then; thus; and now

finally; at last; in the end

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

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 open; to undo; to unseal; to unpack; to bloom; to unfold; to spread out; to open (for business, e.g. in the morning); to be wide (gap, etc.); to widen; to hold (meeting, etc.); to give; to open; to found (nation, dynasty, sect, etc.); to open (a new business); to set up; to establish; to start; to open (ports, borders, etc.); to open (an account); to open up (new land, path, etc.); to clear; to develop; to open (a file, etc.); to extract (root); to reduce (equation); to cut open (fish); to change (kanji into hiragana); to flare (e.g. skirt); to slacken (into a poor posture)