壬

壬 is the ninth of the ten 天干 (Heavenly Stems: 甲乙丙丁戊己庚辛壬癸) which combine with the twelve Earthly Branches (地支) to form the 60-year sexagenary cycle still used in Chinese calendars, traditional medicine, and feng shui. In the wuxing (五行) system 壬 is paired with 阳水 'yang water'. In old enumerations it functioned the way 'A, B, C...' or 'I, II, III...' do in English — so 壬 can label item nine in a list.

Three horizontal strokes plus one vertical — easily confused with 王 (wáng, king) and 玉 (yù, jade). Tip: 壬's middle stroke is the longest of the three horizontals; in 王 the bottom stroke is longest. The character on its own is rare outside calendar/list use, so most encounters are in dates like 壬辰、壬午、壬戌.