Noun | 1. | ![]() propagation - the movement of a wave through a medium wave - a persistent and widespread unusual weather condition (especially of unusual temperatures); "a heat wave" |
2. | wave front - (physics) an imaginary surface joining all points in space that are reached at the same instant by a wave propagating through a medium natural philosophy, physics - the science of matter and energy and their interactions; "his favorite subject was physics" surface - the extended two-dimensional outer boundary of a three-dimensional object; "they skimmed over the surface of the water"; "a brush small enough to clean every dental surface"; "the sun has no distinct surface" |