Coenurus \C[oe]*nu"rus\, n. [NL. fr. Gr. ? + ? tail.]

(Zo["o]l.) The larval stage of a tapeworm (T[ae]nia c[oe]nurus) which forms bladderlike sacs in the brain of sheep, causing the fatal disease known as water brain, vertigo, staggers or gid.

Note: 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.

Source: Webster's Revised Unabridged Dictionary (1913)