Revolutionary means completely new and overturning what came before. A revolutionary design, revolutionary ideas, a revolutionary government.
Advertising has worn it thin — almost nothing described as revolutionary is. The political sense is exact and heavy: a revolutionary wants to overturn the system rather than reform it. Revolution first meant a turning, as of the planets, and still does in mechanics.
1adjectiverevolutionaryCompletely new and overturning what came before.
“The telephone was a revolutionary invention that changed how people communicated.”
revolutionary is a quality of newness.
From revolution, from Latin revolvere, to roll back. The political sense grew from the idea of a complete turn.
Compare French révolutionnaire; equivalent to revolution + -ary.
Etymology from Wiktionary, CC BY-SA