noun
: a figure that is determined by four coplanar lines, and has four sides and three diagonal axes, each two of which cut the other harmonically in three centers of which one or even two may be at infinity
noun
: a figure that is determined by four coplanar lines, and has four sides and three diagonal axes, each two of which cut the other harmonically in three centers of which one or even two may be at infinity
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012