Other forms: boudoirs
Boudoir is a slightly old-fashioned word for a bedroom. You could invite a friend for a sleepover and say, "You can sleep on the spare bed in my boudoir."
These days, the word boudoir is mainly used for its humorous effect. You may also come across it in an old book or movie, almost always referring to a woman's private bedroom. A boudoir is comfortable and luxurious, and the word itself was popular among the upper class in the 18th century, from the French and meaning "pouting room," from bouder, "to pout" or "to sulk."