Bows were a type of projectile weapon commonly used prior to and during the Middle Ages. Arrows were the usual ammunition. They were also used in the sport of archery.
The Outsiders on Gallifrey lived in the wild lands outside the Capitol. They maintained a primitive lifestyle, wore animal skins and used weapons like bows, arrows and spears to hunt for food. While among them, Leela displayed her talent with a bow. (TV: The Invasion of Time)
Crazy Horse taught the Doctor how to use a bow and arrow. (AUDIO: Moonflesh)
The Exxilons, after devolving, used bows and arrows as did the humans stranded on the planet. (TV: Death to the Daleks)
Lady Peinforte fashioned a statue of herself with a bow and arrow out of the validium that landed on Earth in the 17th century. (TV: Silver Nemesis)
The Cobalites were an aggressive species that had only primitive technology and used bows and arrows for weapons. (COMIC: Ground Control)
By the later years of the Thousand Year War on Skaro, apparent supply issues forced some soldiers, such as Kanzo, to make do with bows in place of rifles or energy weapons. (TV: The Magician's Apprentice).