Relating to, or employing, multiple waves (or waves of multiple wavelength)

The stone of a cherry. / (games, obsolete) A children's game in which players attempt to knock marbles into a hole without losing their taw in the same hole.

irremediableness

An assembly of meshed gears consisting of a central (sun) gear, a coaxial internal gear-wheel and one or more intermediate pinions supported on a revolving carrier.