乳溝 にゅうこう Also written ちちみぞ Meanings Noun mammary slit (in whales, dolphins and porpoises) cleavage (between breasts) (esp. ちちみぞ) Kanji 乳 milk. Read as ニュウ. 溝 ditch. Read as コウ. Word lists Zoology Jinuma: Japanese Dictionary · Word lists