lituus

lituus [lit-yoo-uh s] ExamplesWord Origin noun, plural lit·u·i [lit-yoo-ahy] /ˈlɪt yuˌaɪ/.

1. Geometry. a polar curve generated by the locus of a point moving so that the square of its radius vector varies inversely as the angle the radius vector makes with the polar axis. Equation: θr2 = a.
2. (in ancient Rome) a crook-shaped staff used by augurs for divination.

Origin of lituus 1605–15; Latin; geometrical sense from the curve’s resemblance to such a staff Examples from the Web for lituus Historical Examples of lituus

A Roman lituus, or clarion, was found near Tattershall Ferry.

Records of Woodhall Spa and Neighbourhood

J. Conway Walter

Lituus, li-tū′us, n. an augur’s staff with recurved top: a spiral of similar form.

Chambers’s Twentieth Century Dictionary (part 2 of 4: E-M)

Various

The Roman lituus, the chief ensign of the augurs, became the crozier.

History of the Conflict Between Religion and Science

John William Draper

Eckhel infers from the guttus and lituus on one of Sulla’s coins that he was an Augur.

Plutarch’s Lives, Volume II

Aubrey Stewart & George Long