Historically, FWIW, the clerical version of black tie, at least for Roman Catholic Clergy (called abito piano), was cassock, biretta, and a cape called a farraiolo. It's not a kilt, but it is a non-bifurcated garment. (it's also very out of style in the contemporary clergy, and sure to raise a few eyebrows).

http://alturl.com/426wg