volvelle

[ vol-vel ]
/ ˈvɒl vɛl /

noun Astronomy.

a medieval instrument consisting of a series of concentric rotating disks, used to compute the phases of the moon and its position in relation to that of the sun.

Origin of volvelle

1400–50; late Middle English < Medieval Latin volvella, equivalent to Latin volv(ere) to turn + -ella -elle

Words nearby volvelle