köken: Intensification of Middle High German dôz (“sound, noise, din”), ultimately derived from Middle High German diuzen, compare German tosen (“to roar, rage”) and Old English þys (“tempest, storm”).
köken: Inherited from Old Spanish [Term?], probably from a Vulgar Latin *extronĭtus, from *tronĭtus, from metathesis of Latin tonitrus. Compare Portuguese estrondo. Doublet of tronido, which came from a variant with stress on the penultimate syllable (long -i-).