act of improving by expanding or enlarging or refining

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)