Relating to or resembling a gnomon, which is the part of a sundial that casts a shadow. The gnomonical design of the sculpture allowed it to cast intricate shadows on the ground.
Pertaining to gnomonics, the art or science of constructing and using sundials. His dissertation on gnomonical instruments revolutionised eighteenth-century timekeeping.
Based on or employing a gnomonic (central) projection of a sphere. Early polar explorers relied on gnomonical charts to plot their courses.