The Collaborative International Dictionary of English v.0.48:
Blanc \Blanc\ (bl[aum]N), n. [F., white.] 1. A white cosmetic. [Webster 1913 Suppl.] 2. A white sauce of fat, broth, and vegetables, used esp. for braised meat. [Webster 1913 Suppl.]WordNet (r) 3.0 (2006):
blanc n 1: a white sauce of fat, broth, and vegetables (used especially with braised meat)