Definition of Federal Rules of Criminal Procedure
Procedural rules which govern all criminal proceedings in the U.S. District Courts, and, where specified, before U.S. Magistrates. Such rules were promulgated by the U.S. Supreme Court in 1945 under power granted by Congress, and have since been frequently amended. Several states have adopted criminal procedural rules patterned on the federal criminal rules. See 28 U.S.C.A. §§ 2071- 2074.
That's the definition of Federal Rules of Criminal Procedure in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.