elastic: [17] Greek elaúnein meant ‘drive’. From it was derived the late Greek adjective elastikós, which had the sense ‘driving, propelling’. Its Latin version elasticus was used by the French scientist Jean Pecquet (1622–74) in describing the expansive properties of gases, and that is the sense in which it was originally adopted into English. Its transference to the wider meaning ‘returning to a former state after contracting’ took place towards the end of the 17th century. [elastic etymology, elastic origin, 英语词源]