A bed was a type of furniture where individuals slept.
Among the changes the Eleventh Doctor made to the Digby estate when the Arwells visited was taking out the beds in the children's room and replacing them with hammocks. (TV: The Doctor, the Widow and the Wardrobe)
While at the West Country Children's Home, young Danny Pink had a nightmare about something hiding under his bed grabbing him. The Twelfth Doctor and Clara Oswald unintentionally arrive there while investigating that universal nightmare. Later, they landed on Gallifrey in the Doctor's youth, in the barn where he hid to escape being tormented by other children. Clara hid under the bed and grabbed him when he was getting out of it. (TV: Listen)