Source : CEDICT

first of 10 heavenly stems 天干 and first of 12 earthly branches 地支/by ext., the 60 combinations 甲子, 乙丑, 丙寅 etc making up the year cycle/first year A1 of the 60 year cycle, e.g. 1984 or 2044

Source : CEDICT

first of 10 heavenly stems 天干 and first of 12 earthly branches 地支/by ext., the 60 combinations 甲子, 乙丑, 丙寅 etc making up the year cycle/first year A1 of the 60 year cycle, e.g. 1984 or 2044