Burgess v. United States, ___ U.S. ___, ___ (Apr. 16, 2008) ("Burgess urges us to apply the rule of lenity in determining whether the term "felony drug offense" incorporates [21 U.S.C.] 802(13)'s definition of "felony." "[T]he touchstone of the rule of lenity is statutory ambiguity." Bifulco v. United States, 447 U.S. 381, 387, 100 S.Ct. 2247, 65 L.Ed.2d 205 (1980) (internal quotation marks omitted). "The rule comes into operation at the end of the process of construing what Congress has expressed," Callanan v. United States, 364 U.S. 587, 596, 81 S.Ct. 321, 5 L.Ed.2d 312 (1961), and "applies only when, after consulting traditional canons of statutory construction, we are left with an ambiguous statute," United States v. Shabani, 513 U.S. 10, 17, 115 S.Ct. 382, 130 L.Ed.2d 225 (1994). Here, Congress expressly defined the term "felony drug offense." The definition is coherent, complete, and by all signs exclusive. Accordingly, there is no ambiguity for the rule of lenity to resolve.").