The Romans originally called their triumphal arch fornix, not arcus.
A view of this is given by Donati, who calls it the arcus Domitiani.
In elderly persons we ought always to look for the arcus senilis, which is a sign of a tendency to fatty degeneration.
Moreover, there is the arcus senilis, the fine translucent to opaque circle surrounding the outer portion of the iris.
The frustules are curved or arcuate (arcus, a bow) in the side view, oblong and narrowed at the ends in the front view.
Otia si tollas, periere Cupidinis arcus—Remove 45 the temptations of idleness, and Cupid's bow is useless.
The etymology of arcus is the same; the root arc not only means to hurl, but to sing or resound.
Its claim, as the parent of projectile implements, is recognized in the common etymology of arcus, arcualia—artillery.
arcus ar·cus (är'kəs)
n. pl. arcus
A structure resembling a bent bow or an arch.