The crashing or booming sound produced by rapidly expanding air along the path of the electrical discharge of lightning, The destructive agent in a thunder-storm; a discharge of lightning; a thunderbolt, An alarming or statrling threat or denunciation, verb_ be the case that thunder is being heard, to make or produce a loud noise, utter words loudly and forcefully, transitive verb_ To emit with noise and terror; to utter vehemently; to publish, as a threat or denunciation, intransitive verb_ To produce thunder, To produce sounds like thunder, To utter loud, vociferous remarks or threats

That expands, or may be expanded; extending; spreading; enlarging, verb_ Present participle of expand

The application of techniques or technology to the production of new goods or services, act of improving by expanding or enlarging or refining, a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)