unacceptable

Unacceptable is an adjective used to describe something that cannot be accepted or tolerated because it fails to meet established standards, rules, or norms. The term conveys a normative judgment rather than a factual assertion about legality or feasibility. What is considered unacceptable depends on context, culture, and time, and thresholds can shift as circumstances change.

In social and professional settings, unacceptable conduct includes actions that violate rights, safety, or basic standards of respect. Examples include harassment, discrimination, or willful noncompliance with essential procedures. In policy and governance, proposals or outcomes may be deemed unacceptable if they pose undue risk, harm public welfare, or breach fundamental obligations. In risk assessment, an unacceptable level of risk triggers required mitigation or prohibition.

Etymology: from acceptable with the prefix un-, from Middle English un- + acceptable, from Latin acceptabilis, from accipere "to take, receive". Related terms include acceptable, acceptability, and unacceptability; near synonyms include inadmissible and improper.

Unacceptable signals a boundary in evaluation or behavior and often prompts corrective action, renegotiation, or rejection. It is a flexible standard that varies across domains and over time.