開襟かいきん Noun English jmdict 1 noun (common) (futsuumeishi) unbuttoning a collar 2 noun (common) (futsuumeishi) opening up (one's heart) 3 noun (common) (futsuumeishi) abbreviation open-necked shirt See also: 開襟シャツ (かいきんシャツ) Other forms 開衿 【かいきん】