Amicus curiae

friend of the court, person invited by the court to advise it on some matter

Amicus curiae (plural amici curiae) is a legal Latin phrase, literally translated as "friend of the court", that refers to someone, not a party to a case, who volunteers to offer information on a point of law or some other aspect of the case to assist the court in deciding a matter before it. The information may be a legal opinion in the form of a brief - testimony that has not been solicited by any of the parties - or a learned treatise on a matter that bears on the case. The decision whether to admit the information lies with the discretion of the court.
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Noun
1. an adviser to the court on some matter of law who is not a party to the case; usually someone who wants to influence the outcome of a lawsuit involving matters of wide public interest
(synonym) friend of the court
(hypernym) adviser, advisor, consultant
(classification) law, jurisprudence

amicus curiae, friend of the court, person invited by the court to advise it on some matter

Latin: friend of the court. - (read more on Amicus curiae)