Definition of Fide commissary
A term derived from the Latin "fidei-commissarius,” and occasionally used by writers on equity jurisprudence as a substitute for the law French term "cestui que trust, ” as being more elegant and euphonious. See Brown v. Brown, 83 Hun. 160, 31 N.Y.S. 650.
That's the definition of Fide commissary in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.