: a container often somewhat narrowed toward the outlet and often fitted with a closure: such as
a
: a broad flattened necked vessel used especially to carry an alcoholic beverage on the person
b
British
: thermos
Examples of flask in a Sentence
Recent Examples on the Web
For example, when researchers put volcanic sand into a flask and pumped it down to Martian atmospheric pressures, swirling the sand in the flask created a glow that could be seen in the dark, says Ralph Lorenz, a planetary scientist with the Johns Hopkins University Applied Physics Laboratory.
—
Nell Greenfieldboyce, NPR, 26 Nov. 2025
Pictures showed golden jewelry found at the site, as well as a glass flask, a glass jar and other intact items after they were collected.
—CBS News, 21 Nov. 2025
The main hydration pocket holds a 500-milliliter soft flask, and the smaller pockets can carry enough gels for a 50K race.
—Jakob Schiller, Outside, 18 Nov. 2025
Outside food, beverage, liquid containers, alcohol, cans, bottles, flasks (hydroflasks, metal, etc.) or coolers.
—Ed Masley, AZCentral.com, 3 Nov. 2025
See All Example Sentences for flask
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Nell Greenfieldboyce, NPR, 26 Nov. 2025
Pictures showed golden jewelry found at the site, as well as a glass flask, a glass jar and other intact items after they were collected.
—CBS News, 21 Nov. 2025
The main hydration pocket holds a 500-milliliter soft flask, and the smaller pockets can carry enough gels for a 50K race.
—Jakob Schiller, Outside, 18 Nov. 2025
Outside food, beverage, liquid containers, alcohol, cans, bottles, flasks (hydroflasks, metal, etc.) or coolers.
—Ed Masley, AZCentral.com, 3 Nov. 2025
See All Example Sentences for flask
Cite this Entry
“Flask.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flask. Accessed 29 Nov. 2025.
Copy CitationKids Definition
flask
noun
: a container shaped like a flattened bottle
Medical Definition
flask
1 of 2 noun
: a container often somewhat narrowed toward the outlet and often fitted with a closure: as
a
: any of various usually blown-glass vessels used for technical purposes in a laboratory
b
: a metal container in which the materials used to form a dental restoration (as a denture) are processed
flask
2 of 2 transitive verb
: to place (a denture) in a flask for processing
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