Inadmissible

Inadmissible is an adjective describing something that cannot be admitted, accepted, or allowed in a given process or setting. The term is used in everyday language to denote something unacceptable or not relevant, and in formal contexts it has a technical sense, particularly in law. Its etymology traces to the Latin admissibilis meaning capable of being admitted, with the negating prefix in-.

In legal proceedings, inadmissible commonly refers to evidence that the court will not permit to be presented or considered. Evidence may be deemed inadmissible if it fails to meet rules of relevance, reliability, or authenticity, or if it is privileged, duplicative, or obtained unlawfully. Common grounds include hearsay, improper opinion testimony, lack of foundation, prejudice outweighing probative value (where applicable), or violations of the chain of custody or authentication requirements. A judge may sustain objections or issue rulings on admissibility, and in many jurisdictions a motion in limine seeks to exclude such evidence before it is offered at trial.

The effect of inadmissible evidence is that it cannot be used to prove the facts at issue. Inadmissibility can be challenged on appeal if the exclusion is alleged to have affected the trial’s outcome; some errors are subject to harmless-error review or reversible prejudice.

The term also appears in immigration and administrative law, where a person or proposal may be deemed inadmissible if it fails to meet statutory requirements or security, health, or other grounds. In common usage, something described as inadmissible is simply not acceptable for inclusion, consideration, or entry under the applicable rules.