revolutionist (n.)

late 14c., revolucioun, originally of celestial bodies, "one (apparent) rotation about the earth," also the time required for this, also "act or fact of moving in a circular course," from Old French revolucion "course, revolution" of celestial bodies (13c.) or directly from Late Latin revolutionem (nominative revolutio) "a revolving," noun of action from past-participle stem of Latin revolvere "turn, roll back" (see revolve).

From early 15c. as "a cyclical reoccurrence, a round or recurrent changes or events;" also "the revolving of a wheel." By 1660s as "action on the part of an object or person of turning round or moving round a point."

The sense of "an instance of great change in affairs" is recorded from mid-15c. The political meaning "overthrow of an established political or social system" is recorded by c. 1600, derived from French, and was especially applied in England to the expulsion of the Stuart dynasty under James II in 1688 and transfer of sovereignty to William and Mary under a purer constitutional government. Green revolution in global food production is attested from 1970.

"pertaining to or concerned with revolution in government," 1774; see revolution + -ary. As a noun, "one who desires or endeavors to effect social or political revolution," by 1850 (compare revolutionist).