Webster's Revised Unabridged Dictionary · 1913

Cingulum

Cingulum , noun

[Latin, a girdle.]

(a)
(Zoology) A distinct girdle or band of color; a raised spiral line as seen on certain univalve shells.
(b)
(Zoology) The clitellus of earthworms.
(c)
(Zoology) The base of the crown of a tooth.