A woman's menstruation

n. The birth name of somebody who has changed their name. Most commonly attributed to trans people, but can be attributed to any person who has changed their name. (sometimes written as two words: dead name)

v. 1. To call somebody by their deadname.
v. 2. To out somebody's deadname to the public.

Satan's waterfall is another word for having your period. This is referred to satans waterfall because satan means evil and hell (basically what a period is) (oh and because satan normally associates with the colour red like a period) and waterfall means the constant flow of blood.