amplitude antinode crest de Broglie wave diffraction electromagnetic radiation electromagnetic wave frequency frequency band frequency spectrum guided wave ill-considered ill-seasoned ill-timed improper in phase inappropriate inauspicious inconvenient inexpedient infelicitous inopportune intempestive interference intrusive irrelevant late light longitudinal wave mal a propos malapropos mechanical wave mistimed node off base out of line out of time period periodic wave premature radio wave ray reinforcement resonance resonance frequency seismic wave shock wave sound wave surface wave tidal wave too late too soon transverse wave trough unbefitting unfavorable unfit unfitting unfortunate unhandy unhappy unlucky unpropitious unready unripe unseasonable unsuitable untimely untoward wave wave equation wave motion wave number wavelength wrong