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

胸腔[kyoukou] thorax
口腔外科[koukuugeka] dental surgery
耳腔[jikou] inside the ear
体腔[taikou] body cavity
体腔壁[taikouheki] body wall

内腔[naikou] lumen (anatomical)
口腔[koukou] the oral cavity
鼻腔[bikou] the nasal cavity
腹腔[fukkou] abdominal cavity
口腔癌[koukougan] oral cancer