A more thorough explanation:

de lunatico inquirendo

De lunatico inquirendo is a legal term that means "for inquiring about a lunatic." It refers to a writ or commission that is used to determine whether a person is mentally ill or insane.

An example of de lunatico inquirendo would be if a family member or friend was concerned about someone's mental health and wanted to have them evaluated. They could petition the court for a commission of lunacy to be issued, which would allow for a legal investigation into the person's mental state.

Another example would be if someone was accused of committing a crime but was found to be mentally incompetent to stand trial. A commission of lunacy could be used to determine whether the person was truly mentally ill or if they were faking it to avoid prosecution.

These examples illustrate how de lunatico inquirendo is used in a legal context to determine whether someone is mentally ill or not. It is an important tool for protecting the rights of individuals who may not be able to make decisions for themselves due to mental illness.