Pudendum is a very formal, mostly medical word for the sexual organs on the outside of the body, especially a woman's (the vulva). Doctors may say the pudendum, but in Latin and in English the plural pudenda was always the more common form. Ordinary people do not use this word; they say private parts, or a doctor will use a plainer anatomy term. It comes from Latin pudenda, that whereof one ought to feel shame, from pudet, it shames. That origin tells you how older European language packed shame into the name for the body — worth noticing, not copying. In anatomy you will also meet pudendal, as in the pudendal nerve. This is not a word for the classroom joke or for chatting with friends.