Pronunciation: [plˈe͡ɪn ˈɛɹə] (IPA) 
The spelling of "plain error" is straightforward, but its pronunciation is not always so clear. In IPA phonetic transcription, "plain" is pronounced /pleɪn/, with a long "a" sound and emphasized "n" at the end. "Error" is spelled /ˈerər/, with the emphasis on the first syllable and a short "e" sound. Together, "plain error" refers to a mistake that is so obvious or significant that it warrants correction by an appellate court.
Plain error is a legal concept used in the United States that refers to a fundamental and prejudicial error made during a trial or legal proceeding that was not objected to by the opposing party at the time it occurred. It is a type of error that is so obvious and substantial that it may have affected the outcome of the case, regardless of whether an objection was raised.
In order for an error to be considered plain, it must be so clear and apparent that even a non-lawyer or layperson would recognize it as a mistake. It cannot be a subtle or technical error but rather a glaring error that goes against the fundamental principles or rights of the legal system.
When a plain error is identified, it can be raised even if it was not raised during the trial or proceeding. This means that the party who suffered from the error can still bring it to the court's attention on appeal. However, due to the failure to object at the appropriate time, a plain error must meet a higher standard for correction than regular errors. The error must have been so prejudicial and substantial that it undermines the integrity and fairness of the entire legal process or seriously affects the outcome of the case.
Overall, plain error is a serious and significant mistake made in a legal proceeding that can potentially impact the outcome of a case, even if it was not brought up or objected to at the time it occurred.
The word "plain error" originated from Middle English and evolved from Old French "plain" which means "clear" or "evident". In this context, "plain" refers to an error that is clearly and unmistakably incorrect. Over time, the term "plain error" came to be used in legal settings to describe an obvious mistake or error in a court proceeding. It is often used to refer to an error that is so obvious that it does not require additional explanation or analysis.
