癸

guǐ

天 + 癶

Definitions

guǐ tenth of the ten Heavenly Stems 十天干[shí tiān gān]; tenth in order; letter "J" or Roman "X" in list "A, B, C", or "I, II, III" etc; ancient Chinese compass point: 15°; deca

Etymology

Possibly depicts a type of ancient weapon with three points on it. Based on the original meaning "a type of weapon", now written as 戣. The current meaning is a phonetic loan.

About

癸 (guǐ) is the tenth and last of the Heavenly Stems, used in traditional Chinese calendrical, astrological, and cosmological systems. Although its modern form is commonly parsed as 癶 (bō, spread legs or footsteps) placed above 天 (tiān, sky), this breakdown does not reflect the character's origin. It likely began as a pictograph of an ancient weapon with three points, a meaning now written as 戣, and was borrowed phonetically for the stem. Within Five Elements theory, 癸 corresponds to Yin Water, winter, and the northern direction. The character also appears in traditional Chinese medicine in the term 天癸 (tiān guǐ), where it denotes menstruation and the reproductive cycle.