An Entry Monday, October 19, 2026
The Thiccctionary
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A round-bottom flask holding a sprouting seed in water, resting on a Kinfolk magazine.

Plate CXLIV. A round-bottom flask holding a sprouting seed in water, resting on a Kinfolk magazine.

Photo by Daniel Öberg on Unsplash

Round-Bottom Flask

/round-BOT-tum flask/  n.
  1. 1. A laboratory flask of borosilicate glass, a slim neck set on a perfectly spherical body, designed to heat evenly from every side; so round at the base that it cannot stand unaided and is ordinarily seated in a cork ring.
  2. 2. colloq. All neck up top, then the whole sphere at once. She cannot sit on a flat bench without a cushion, and nobody in the lab has ever asked her to try.
In a sentence:

"The TA set a thiccc 1000 mL round-bottom flask on the bench in Organic Chem II and it rolled straight into the sink. Nothing that round sits on a flat surface without a cork ring."

Etymology:

From Medieval Latin flasca, a bottle, by way of French flasque; 'round-bottom' was added by chemists to tell her apart from the flat-bottomed flask, which can stand up on its own and has never once been the topic of conversation.

From the desk

Filed by

Teddy VanceJunior Cataloguer

The spherical lower portion is a closed, uninterrupted curve with absolutely nowhere left to go but inward, and it does not.

Ruling ADMITTED

Bart PrussSenior Cataloguer

The base is a complete sphere. Glass does not negotiate. Admitted.

In the margin

Eliza HartwellStaff Writer

The lab assistant's eyebrows raised in the example sentence. The flask was on a burner. The eyebrows had priorities.

Frequently asked

Is a round-bottom flask thiccc?

Yes. Round-Bottom Flask was admitted to the Thiccctionary on October 19, 2026 and filed in the Industrial Machinery section. The ruling on file: Admitted. Every subject in the catalogue is judged on its curves, not its size.

What makes a round-bottom flask thiccc?

All neck up top, then the whole sphere at once. She cannot sit on a flat bench without a cushion, and nobody in the lab has ever asked her to try.

Is "thiccc" spelled with three c's?

Yes. The Thiccctionary house spelling uses three c's, distinguishing the editorial register from the colloquial "thicc" (two c's) and standard "thick" (one c).

Sources

  1. Photograph by Daniel Öberg, via Unsplash. Catalogued under plate CXLIV.
  2. Direct ruling URL: thiccctionary.com/is/round-bottom-flask-thiccc/, the shareable "Is a round-bottom flask thiccc?" page.
  3. Cross-reference: Thiccctionary A-Z, R.
  4. Catalogued under: Industrial Machinery. See related entries below.
  5. Editorial review: ruled admitted by the desk. Objections on file.

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