lunetted

All were precisely similar in shape and proportions, radiating in a lunetted, curved base triangle from the middle chamber; the curvature of the enclosing globe forming back wall and roof; the translucent slicings the sides; the circle of floor of the inner hall the truncating lunette.

The Metal Monster 2004

That flattish, dark disc, with lunetted edge, rising erect above the surface, and cutting keenly through the rippling water, was an object not to be mistaken for any moving thing met with amid the ocean, save the dorsal fin of a shark, and William knew at a glance that such in reality it was.

The Ocean Waifs A Story of Adventure on Land and Sea Mayne Reid 1850