(analytical chemistry) A form of chromatography in which the solid phase is silica gel or a similar inert material supported on a glass plate.

(analytical chemistry) Alternative spelling of thin-layer chromatography

(meteorology) The portion of the atmosphere lying next to the surface of the earth and extending up to between 50 and 100 meters.

A layer of ionized gas occurring between roughly 90–150 km (56–93 mi) above the ground. It reflects medium-frequency radio waves, and thus enables them to be propagated beyond the horizon.

plural of Kennelly-Heaviside layer

Synonym of dual federalism

A cake consisting of seven thin layers of baked batter interlaced with seven layers of frosting.

An American appetizer containing layers of ingredients typical of Tex-Mex cuisine.

An American salad dish containing layers of vegetables and other ingredients.

plural of surface boundary layer