The Collaborative International Dictionary
Gnomonical
Gnomonic \Gno*mon"ic\, Gnomonical \Gno*mon"ic*al\, a. [L. gnomonicus, Gr. ?: cf. F. gnomonique. See Gnomon.] Of or pertaining to the gnomon, or the art of dialing.
Gnomonic projection, a projection of the circles of the
sphere, in which the point of sight is taken at the center
of the sphere, and the principal plane is tangent to the
surface of the sphere. ``The gnomonic projection derives
its name from the connection between the methods of
describing it and those for the construction of a gnomon
or dial.''
--Cyc. of Arts & Sciences.
Wiktionary
gnomonical
a. (alternative form of gnomonic English)