flask
n. countablen. a container used to hold liquids. In a kitchen, it often keeps drinks hot or cold; in a science lab, it is a glass bottle with a special shape for experiments.
n. a container with a narrow neck used to hold liquids, typically made of glass for laboratory use or insulated metal for maintaining temperature.
He poured hot coffee from his flask into a cup.
The chemist carefully swirled the blue liquid inside the glass flask to ensure the chemicals mixed thoroughly.
To maintain the integrity of the sample, the researcher transferred the solution into a vacuum-insulated flask designed to prevent any thermal exchange with the external environment.
From Middle English flask, flaske (“case, cask, keg”), from Old English flasce, flaxe (“bottle, flask”) and Medieval Latin flascō (“bottle”); from Frankish flaskā; both from Proto-Germanic flaskǭ (“braid-covered bottle, wicker-enclosed jug”), from Proto-Indo-European ploḱ-skō (“flat”), or from Proto-Indo-European pleḱ- (“to weave”). Doublet of fiasco, flacon, and flagon. Related to Dutch fles; also German Low German Flaske, Fless, German Flasche, Danish flaske; also Lithuanian plókščias, Czech ploský, Albanian flashkët. The sense “laboratory glassware” is from Italian fiasco, and the sense “container for holding a casting mold” is from Middle French flasque (“powder flask”), itself from Old Spanish flasco, frasco, both from Late Latin above.
In British English, often refers specifically to a vacuum flask (Thermos); in American English, frequently refers to a small, flat container for alcohol.