Thun'der·ing adjective 1. Emitting thunder. « Roll the thundering chariot o'er the ground.» J. Trumbull. 2. Very great; -- often adverbially. [ Slang] -- Thun'der*ing*ly , adverb Found on http://www.encyclo.co.uk/webster/T/52
adjective extraordinarily big or impressive; `a thundering success`; `the thundering silence of what was left unsaid` Found on https://www.encyclo.co.uk/local/20974