thunderless,a.|ˈθʌndəlɪs| [f. thunder n. + -less.] Unaccompanied by thunder (or noise like thunder). 1855G. Meredith Shav. Shagpat (1856) 371 Flashes of thunderless lightnings.1880Tennyson Voy. Maeldune iii, The long waterfalls Pour'd in a thunderless plunge to the base of the mountain walls.