thunderful,a.rare.|ˈθʌndəfʊl| [f. thunder n. + -ful.] Full of or charged with thunder; loosely, thundering, sounding like thunder. 1898G. Meredith Day of Daughter of Hades ix, Legions of thunderful horse.1910Westm.Gaz. (weekly ed.) 30 Apr. 6/3 As clouds that are thunderful.