From Middle English flask (“cask, keg”), from flaske (“case”), from Anglo-Norman flascon, from Late Latin flascō (“bottle”), from Frankish *flasko (whence also Dutch fles), from Proto-Germanic *flaskǭ (“braid-covered bottle, wicker-enclosed jug”) (whence also Old English flaxe, flasce, German Flasche), from Proto-Indo-European *ploḱ-skō (“flat”) (whence also Lithuanian plókščias, Czech ploský).
flask (plural flasks)
- A container used to discreetly carry a small amount of a hard alcoholic beverage; a pocket flask.
- (sciences) 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.
- (engineering) A container for holding a casting mold, especially for sand casting molds.
- Imperative of flaske.