Dictionary:

mousseline

  (mūs-lēn')

1. A fine sheer fabric resembling muslin, originally made in Mosul, Iraq.
2. A hollandaise sauce to which whipped cream has been added.
3. An aspic containing whipped cream.

[French. See muslin.]

French; general term for light, fluffy dish. Mousseline sauce is Hollandaise sauce to which beaten egg-white or whipped cream is added just before serving, to give a frothy texture.

[moos-LEEN] 1. Any sauce to which whipped cream or beaten egg whites have been added just prior to serving to give it a light, airy consistency. Mousseline sauce is hollandaise blended with whipped cream. 2. Various dishes based on meat, fish, shellfish or foie gras (usually puréed) to which whipped cream or, less frequently, beaten egg whites are added to lighten the texture. 3. A term applied to any of various dishes or baked goods that have a light and delicate texture.