1. not allowed to be admitted or accepted, especially as evidence in a court of law
Usage: legal
2. not acceptable or allowable in a particular situation

Examples

• The judge ruled that the confession was inadmissible because it was obtained illegally.
• Hearsay evidence is generally inadmissible in criminal trials.
• The lawyer objected that the witness’s testimony was inadmissible.
• Such behavior is inadmissible in a professional workplace.
• The court found the documents inadmissible due to improper authentication.
• His excuse for being late was inadmissible given the circumstances.