Echinus n. : A hedgehog.

Echinus n. : A genus of echinoderms, including the common edible sea urchin of Europe.

Echinus n. : The rounded molding forming the bell of the capital of the Grecian Doric style, which is of a peculiar elastic curve. See Entablature.

Echinus n. : The quarter-round molding (ovolo) of the Roman Doric style. See Illust. of Column

Echinus n. : A name sometimes given to the egg and anchor or egg and dart molding, because that ornament is often identified with Roman Doric capital. The name probably alludes to the shape of the shell of the sea urchin.

Example:
How would you build the curved Echinus of a wood parthenon?

Taxonomy
Echinus, free encyclopedia, genus, search, plant, molding, window manager, synonym, animals, X11, layouts, disambiguation pages, Personal tools, Interaction, Toolbox, non-profit organization, Mallotus, sea urchin.

Defination from the web:
Echinus (sea urchin), a genus of animals. Molding (decorative), similar to the ovolo molding. Echinus (window manager), a window manager for X11 supporting managing windows in floating, tiled and maximized layouts. ...