A longbow was a type of weapon.
In eastern Europe in the 11th century, Adric instructed Udilf's people in the construction and use of longbows, much to the Fifth Doctor's disapproval. (PROSE: The Immortals)
In an alternate timeline where Polly Wright was manipulated into interfering with temporal nexus points, Mang accidentally killed Adric with a longbow when he was distracted by Polly's sudden appearance. (PROSE: That Time I Nearly Destroyed the World Whilst Looking for a Dress)