(n)an equal-area map projection showing parallels and the equator as straight lines and other meridians as curved; used to map tropical latitudes, Syn.Sanson-Flamsteed projection
n. [ Sinus + -oid. ] (Geom.) The curve whose ordinates are proportional to the sines of the abscissas, the equation of the curve being y = a sin x. It is also called the curve of sines. [ 1913 Webster ]