‖n. [ NL. fr. Gr. koino`s common + o'yra` tail. ] (Zool.) The larval stage of a tapeworm (Tænia cœnurus) which forms bladderlike sacs in the brain of sheep, causing the fatal disease known as water brain, vertigo, staggers or gid. [ 1913 Webster ]

☞ This bladder worm has on its surface numerous small heads, each of which, when swallowed by a dog, becomes a mature tapeworm in the dog's intestine. [ 1913 Webster ]