陥かん没ぼつ乳にゅう頭とうMeaningsNoun1. inverted nipple; retracted nippleKanji used陥cave in没go under乳milk頭headComposed of陥かん没ぼつcave-in; collapse; sinking; depression (e.g. of the skull); subsidenceNoun乳にゅう頭とう(mammary) nipple; teatNoun