ELAS'TICAL, adjective [from the Gr. to impel, to drive.] Springing back; having the power of returning to the form from which it is bent, extended, pressed or distorted; having the inherent property of recovering its former figure, after any external pressure, which has altered that figure, is removed; rebounding; flying back. Thus a bow is elastic and when the force which bends it is removed, it instantly returns to its former shape. The air is elastic; vapors are elastic; and when the force compressing them is removed, they instantly expand or dilate, and recover their former state.