Amorphousness refers to the lack of a defined shape or structure, often applied to materials that do not have a crystalline form. In the context of chemistry and materials science, it describes substances like glass or certain polymers that exhibit a disordered arrangement of molecules. This property can affect the physical characteristics, such as transparency, brittleness, and thermal stability, of the material. Amorphous materials can also have unique properties compared to their crystalline counterparts, making them valuable in various applications.