かいこう 開口 Common word LinksSentence search for 開口Sentence search for かいこうKanji details for 開 and 口Edit in JMdict Noun, Suru verb1. opening; aperture (e.g. camera)Noun, Suru verb2. opening one's mouth; beginning to speakNoun or verb acting prenominally3. open; broad Discussions Log in to talk about this word.