bell jar

American  

noun

1. a bell-shaped glass jar or cover for protecting delicate instruments, bric-a-brac, or the like, or for containing gases or a vacuum in chemical experiments.

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bell jar British  

noun

1. a bell-shaped glass cover used to protect flower arrangements or fragile ornaments or to cover apparatus in experiments, esp to prevent gases escaping

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Etymology

Origin of bell jar

First recorded in 1875–80

Example Sentences

They used precision-milled steel to construct the capsule and designed a special bell jar to surround it in a layer of dry air, protecting the inside from the moist soil of the American northeast.

From The Wall Street Journal • Apr. 21, 2026

Again: What works within the humid environment under a bell jar or inside a narrow-mouthed lab flask is quite different from what flourishes in an open bowl or an uncovered fish tank.

From Seattle Times • Dec. 20, 2021

I feel my head is encased in some kind of — like I said, I write about the bell jar.

From Salon • Jan. 19, 2020

For example, the kilogram will no longer be compared with a cylinder of metal sitting under a bell jar outside Paris.

From The Guardian • Dec. 22, 2019

Plus, my sister pointed out one very important detail that helped me emerge from the bell jar: senior prom was the only prom that really mattered.

From "Americanized" by Sara Saedi