Supercooling is the process of cooling a liquid below its freezing point without it solidifying. This can happen when the liquid is very pure and there are no nucleation sites for crystals to form. Supercooling can also occur when a liquid is cooled very quickly, so that the molecules do not have time to rearrange themselves into a crystalline structure.
Supercooling can be a problem in a number of industrial and scientific applications. For example, supercooled water can freeze suddenly and cause damage to pipes and equipment. Supercooling can also interfere with the growth of crystals, which can be used to make semiconductors and other electronic materials.