involute

Several daguerreotypes here foreground the ornament and patterning of Egyptian buildings; this one captures every edge of the involute roof of a 16th-century mosque, festooned with knotty hearts and flowers.

They were involute, introvert, indirect; they did not like questions and answers.

Lip barely saccate below, tapering and its sides involute above; anther ovate, long-pointed, borne on the base of the very short column, which is continued above the stigma into a conspicuous tapering awl-shaped gland-bearing beak.

Draw setting tangent from “base circle” of involute, at middle of tooth.

The first curve is called the involute of the second.