Webster's Revised Unabridged Dictionary · 1913

Flask

Flask (flask or flȧsk) , noun

[Anglo-Saxon flasce, flaxe; akin to Dutch flesch, Old High German flasca, German flasche, Icelandic & Swedish flaska, Danish flaske, Old French flasche, Late Latin flasca, flasco; of uncertain origin; compare Latin vasculum, dim. of vas a vessel, Greek fla`skh, fla`skwn, fla`skion. Compare Flagon, Flasket.]

1.
A small bottle-shaped vessel for holding fluids; as, a flask of oil or wine.
2.
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.
3.
A bed in a gun carriage. [Obsolete] — Bailey
4.
(Founding) The wooden or iron frame which holds the sand, etc., forming the mold used in a foundry; it consists of two or more parts; namely, the cope or top; sometimes, the cheeks, or middle part; and the drag, or bottom part. When there are one or more cheeks, the flask is called a three part flask, four part flask, etc.
Collocations (3)
Erlenmeyer flask , a thin glass flask, flat-bottomed and cone-shaped to allow of safely shaking its contents laterally without danger of spilling; -- so called from Erlenmeyer, a German chemist who invented it.
Florence flask , (a) Same as Betty, n., 3. (b) A glass flask, round or pear-shaped, with round or flat bottom, and usually very thin to allow of heating solutions.
Pocket flask , a kind of pocket dram bottle, often covered with metal or leather to protect it from breaking.