Deutsch: Sprödigkeit / Español: Fragilidad / Français: Fragilité / Italiano: Fragilità
A material is brittle if, when subjected to stress, it breaks without significant deformation (strain). Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound. Brittle materials include most ceramics and glasses (which do not deform plastically) and some polymers, such as PMMA and polystyrene. Many steels become brittle at low temperatures (see ductile-brittle transition temperature), depending on their composition and processing.

In the industrial and industry context, "brittle" refers to materials or substances that have low resistance to breaking or cracking under stress or strain, lacking the ability to bend or deform. Brittle materials tend to fracture suddenly and easily, which can result in significant damage to products or equipment, or even injury to personnel.