御猪口[ochoko] small cup
片口鰯[katakuchiiwashi] Japanese anchovy (Engraulis japonica)
白口[shiroguchi] white croaker (Pennahia argentata)
悪たれ口[akutareguchi] abuse
悪口雑言[akkouzougon] all kinds of malicious gossip

異口同音[ikudouon] in concert
異口同音に[ikudouonni] in one voice
ひと口[hitokuchi] mouthful
一口商い[hitokuchiakinai] an immediate definite deal
一口同音[ikkudouon] reading in unison

噤む[tsugumu] to shut one's mouth

口を噤む[kuchiwotsugumu] to hold one's tongue