A perfectly innocent word, right? Well, not quite. Of course, it is the word from which perfectly innocent words like sijon (yesterday), sijah (today) and sijehi (tomorrow) were created (via irregular derivation, the Juniversiti Junis (the in-universe creators of the rejistanian language) did not do good work here), and it is used in the calque for birthday: sijiv’het mevika. However, one expression is for something… quite bad and private: Sijiv’het’ny redy (red days) refers to that time of the month, premenopausal women have. Rejistanian does not have the range of expressions related to menstruation a Láadan does (there are always adjectives though 🙂 ), but I suspect many conlangs which were not created as auxlangs or by women lack this term.