It is generally necessary to avoid crowded rooms and the vertiginous influence of the dance, one 19th-century medical work advised. We're not sure what condition this advice was aimed at, but it may well have been "vertigo," a disordered state characterized by whirling dizziness. "Vertiginous," from the Latin vertiginosus, is the adjective form of "vertigo," which in Latin means a turning or whirling action. Both words descend from the Latin verb vertere, meaning "to turn." ("Vertiginous" and "vertigo" are just two of an almost dizzying array of "vertere" offspring, from "adverse" to "vortex.") The "dizzying" sense of "vertiginous" is often used figuratively, as in "vertiginous medical discoveries may drastically change life in the 21st century."