Clothing which is worn exclusively to sleep in. They can be fairly simple, lightweight garments or heavy flannel things made to keep you warm in winter. Some pajamas seem to be designed solely for seduction.

Little kids get to wear pajamas with cute little feet sewn onto the legs. Grownups do not really wear pajamas as often, but if you do, you can go out and get the newspaper in the mornings without having to get dressed first.

No matter what you may read in children's books, llamas do not wear pajamas.