姅 [bàn]
1. Refers to women's menstruation, childbirth, miscarriage, etc.
Meaning:
- Menstruation (English: menses)
Reference:
1. *Shuo Wen*: 姅, pertains to the dirtiness of women. It is composed of the female radical and the sound "ban."
2. *Han Law*: If bleeding occurs, one cannot serve at the altar.