unforeseeable

Unforeseeable is an adjective describing events, outcomes, or information that cannot be anticipated or predicted given the circumstances and the knowledge available at the time. In ordinary usage, an unforeseeable event lies outside the range of what a reasonable person could have anticipated under the circumstances. What counts as reasonable can vary by context, expertise, and time.

Etymology and form: The word is built from the prefix un-, the verb foresee, and the suffix -able. It is first attested in English in the 15th century and has since become common in legal, scientific, and technical writing.

Legal and practical use: In contract and tort law, foreseeability is a standard that guides liability and remedies. An event that is reasonably foreseeable may trigger responsibilities, while unforeseeable events can excuse or limit liability. In risk management, the distinction informs contingency planning and insurance arrangements. In everyday language, terms such as “unforeseen circumstances” describe situations that could not have been predicted given the information available, though assessments of foreseeability can be contested and time-dependent.

Related concepts include foreseeability, contingency planning, force majeure, and risk assessment.