flask

noun

1. A narrow-necked vessel of metal or glass, used for various purposes; as of sheet metal, to carry gunpowder in; or of wrought iron, to contain quicksilver; or of glass, to heat water in, etc.
2. A container used to discreetly carry a small amount of a hard alcoholic beverage; a pocket flask.
3. Laboratory glassware used to hold larger volumes than test tubes, normally having a narrow mouth of a standard size which widens to a flat or spherical base.
4. A container for holding a casting mold, especially for sand casting molds.
5. A bed in a gun carriage.
6. A nuclear flask, a large, secure lead-lined container for the transport of nuclear material.

   “Over the years, the railway has been the safest way to move hazardous chemicals, radioactive waste, fuel for Royal Navy nuclear submarines and imported fuel for reprocessing, as well as flasks containing fuel rods to and from British power stations.”

7. (Newfoundland)A small bottle of liquor.

verb

1. To invest a denture in a flask so as to produce a sectional mold.