1. the 10 heavenly stems 甲 (jiǎ), 乙 (yǐ), 丙 (bǐng), 丁 (dīng), 戊 (wù), 己 (jǐ), 庚 (gēng), 辛 (xīn), 壬 (rén), 癸 (guǐ), used cyclically in the calendar and as ordinal numbers I, II etc