An image of the substance known as aerogel.
aerogel definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a substance formed by the suspension of small bubbles of gas in a liquid or solid: the reversal of an aerosol
Origin: aero- plush gel
designating or of a small container in which gas under pressure is used to aerate and dispense foam through a valve
aerogel definition by American Heritage Dictionary
A highly porous solid formed from a gel, such as silica gel, in which the liquid is replaced with a gas.