Sentence:  On motion of the <WSD>amici</WSD> curiae , the court directed that a ruling be obtained from the Commissioner of Internal Revenue as to the federal income tax consequences of the Government 's plan . 
Meaning of the word marked with <WSD> tags:  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