beurre blancPronunciation: /bəː ˈblɒ̃, bœʀ blɑ̃/Definition of beurre blanc noun [mass noun] a creamy sauce made with butter, onions, and vinegar or lemon juice, usually served with seafood dishes. Origin:French, literally 'white butter'beurre blanc in other Oxford dictionaries Definition of beurre blanc in the US English dictionary