repäisy

Repäisy is a Finnish noun meaning the act or result of tearing or ripping something apart, typically produced by a sudden or strong force. It can describe everyday tearing of materials such as paper, cloth, or plastic, as well as a broader event where a material fails by ripping. The term comes from the verb repäistä ("to tear, rip") and forms with the suffix -isy to denote the process or phenomenon.

In technical contexts, repäisy is used in discussions of material strength and failure. Phrases such as repäisyvoima (tearing force) and repäisylujuus (tear strength) describe how a material resists tearing under load, and tests may measure the force required to initiate or propagate a tear. The concept is closely related to other forms of fracture such as rupture and shear, though repäisy emphasizes the ripping mechanism.

Metaphorically, repäisy can refer to a sudden rupture or break in a non-physical sense, such as a rupture in plans, relationships, or a sequence in a narrative.

See also: repäistä, repäisyvoima, tear strength.