Meaning of 口を開く in Japanese

It seems that your search contains the following:

Definition of 口を開く

くちをひらく(kuchiwohiraku) 【口を開く】

(exp, v5k) to open one's mouth (to talk)
私は口を開くとすぐに彼女が私をさえぎった。
I had hardly opened my mouth, when she interrupted me.

いとぐちをひらく(itoguchiwohiraku) 【糸口を開く ·緒を開く】

彼女かのじょはあまりしゃべらないが、いったん口を開くくちをひらくと弁が立つべんがたつ。

She doesn't talk much, but once she does speak she is eloquent.

彼かれは口を開くくちをひらくと必ずかならず何かしらなにかしら不満ふまんを言う。

He never opens his mouth without complaining about something.