bigarade

1. See sour orange.
2. A rich sauce served with duck, consisting of thickened stock flavored with the rind of bitter oranges, lemon juice, and sugar.

[French, from Provençal bigarrado, from past participle of bigarrar, to variegate, from Old French bigarrer : bi-, two (from Latin; see bi-¹) + garrer, to variegate (from garre, of two colors).]

[bee-gah-RAHD] French for "bitter" orange.

The noun has one meaning:

Meaning #1: any of various common orange trees yielding sour or bitter fruit; used as grafting stock
  Synonyms: sour orange, Seville orange, bitter orange, bitter orange tree, marmalade orange, Citrus aurantium