undesired

Undesired is an adjective meaning not wished for or not sought after. It describes things that are negative, unwelcome, or not intended. The term is formed by adding the prefix un- to desired, a process that traces back to the broader origins of the word desire and its Latin roots. In everyday language, people talk about undesired results, undesired consequences, or undesired items when outcomes do not meet expectations or are not welcomed.

In professional contexts, undesired is used to label effects or behaviors that are not intended or are problematic. In medicine and pharmacology, undesired effects (often described as adverse effects) refer to side effects of a drug that are not wanted by patients or clinicians. In engineering and computing, undesired outputs or undesired behavior denote system states or results that should be avoided or corrected through design, testing, or debugging. In risk assessment and policy analysis, undesired outcomes are those that researchers or decision-makers seek to prevent or minimize.

Undesired is closely related to, but distinct from, unintended. Unintended emphasizes lack of intention, while undesired emphasizes a value judgement about desirability. Other near-synonyms include unwanted and undesirable, though usage can vary by domain and formality. Overall, undesired serves as a neutral descriptor for anything not wanted or not appropriate within a given context.