strict

Strict is an adjective describing adherence to rules, standards, or expectations with little tolerance for deviation. It can also refer to something drawn tight or precise, conveying severity or rigorous discipline. The word comes from Latin strictus, meaning drawn tight.

In mathematics and logic, strict denotes exclusion of equality or looseness. A strict inequality, written as < or >, excludes equality; in contrast, ≤ or ≥ are non-strict (weak) inequalities. A strict partial order is a relation that is transitive and irreflexive, and strict implication (→) in logic is stronger than material implication. In other domains, a strict interpretation applies rules exactly as written rather than more loosely or permissively.

In computing, strict evaluation evaluates function arguments before the function is applied; non-strict or lazy evaluation defers evaluation until needed. JavaScript’s strict mode, activated by the directive "use strict," opts into a restricted subset of the language that catches certain errors and forbids some problematic constructs, improving reliability and security.

In legal terms, strict liability imposes responsibility for harms without proof of negligence, often in inherently dangerous activities. Strict scrutiny is a high standard of judicial review used to test laws affecting fundamental rights or suspect classifications, requiring a compelling government interest and narrow tailoring.

Beyond technical uses, strict commonly describes policies or behavior characterized by exacting standards or rigorous enforcement, such as a strict policy, strict discipline, or a strict adherence to guidelines.