the.com/revolutionist

means A person who actively works to overthrow a political or social system, rather than just grumbling about it.

from Built straightforwardly from 'revolution' (from Latin 'revolvere,' to turn or roll back) plus the agent suffix '-ist.' 'Revolution' itself drifted from its original astronomical sense — the turning of planets through their orbits — into political language around the 17th-18th centuries, on the idea of a society completing a full, dramatic turn. 'Revolutionist' and its cousin 'revolutionary' both emerged as the English Enlightenment and French Revolution made the word suddenly very necessary.