Picture a Roman crowd erupting into panic and you have the etymology of disturb. Latin disturbāre combined dis- (apart, completely) with turbāre (to throw into disorder), itself from turba, meaning 'crowd' or 'commotion.' The Greek source tyrbē described the confused noise and movement of a disordered group. Roman writers used disturbāre for the physical scattering of a mob or the disruption of an assembly — it was a word of civic chaos. Old French inherited the verb as destorber, meaning to hinder or confuse, and English borrowed it in the thirteenth century for interference with normal order. The psychological sense came later, emerging in the sixteenth century when disturbed began describing a troubled mind rather than a troubled street. The turba family is one of the liveliest in English. Turbulent keeps the crowd-chaos imagery. Turbine, coined in the 1820s by French engineer Claude Burdin, applied the spinning-commotion metaphor to water power. Trouble arrived from Old French troubler, which described the muddying of clear water — disturbed sediment clouding what was once transparent. Even the adjective turbid (cloudy, opaque) belongs here, proving that one Latin crowd scene could generate seven centuries of English vocabulary.