fidelitet

Fidelitet is a Danish noun meaning faithfulness, loyalty, or accuracy, depending on context. The word derives from Latin fidelitas via French fidélité and English fidelity; in Danish it is used for both personal and technical senses.

In interpersonal contexts, fidelitet refers to loyalty and constancy within relationships, such as romantic fidelity or marital fidelity—keeping promises and being trustworthy. In organizational or political contexts, it can denote allegiance to a group, institution, constitution, or ideology, or to a brand or company.

In technical usage, fidelitet describes how accurately a representation, device, or signal reflects its source. High-fidelity (hi-fi) systems aim to reproduce sound with minimal distortion. In science and engineering, measurement or simulation fidelity reflects closeness to the real phenomenon; low-fidelity models are simpler approximations.

Culturally, fidelity is valued as a virtue in many societies and is linked to ethics and identity. See also related terms such as loyalty and allegiance.