late 14c., "violent movement or agitation, emotional disturbance," from Old French commocion "violent motion, agitation" (12c., Modern French commotion) and directly from Latin commotionem (nominative commotio) "violent motion, agitation," noun of action from past participle stem of commovere "to move, disturb," from com "with, together," perhaps here "thoroughly" (see com-) + movere "to move" (from PIE root *meue- "to push away").

From mid-15c. as "public unrest or disturbance." Verbs commote "to disturb, stir up" (1852), commove (late 14c.) are marked "rare" in Century Dictionary.

"government by the rabble," 1580s, from French ochlocratie (1560s), from Greek okhlokratia (Polybius) "mob rule," the lowest grade of democracy, from kratos "rule, power, strength" (see -cracy) + okhlos "(orderless) crowd, multitude, throng; disturbance, annoyance," which is probably literally "moving mass," from PIE *wogh-lo-, suffixed form of root *wegh- "to go, move."  "Several possibilities exist for the semantic development: e.g. an agent noun *'driving, carrying, moving', or an instrument noun *'driver, carrier, mover'. ... An original meaning 'drive' could easily develop into both 'stirred mass, mob' and 'spiritual excitement, unrest'" [Beekes]. For sense development, compare mob (n.). Related: Ochlocrat, ochlocratic; ochlocratical. Greek also had okhlagogos "mob-leader, ochlagogue."