petri dish

noun

pe·​tri dish ˈpē-trē- 

variants or less commonly Petri dish

plural petri dishes also Petri dishes

1

: a small shallow usually round dish of thin glass or plastic with a loose cover used especially for growing cells or microorganisms on a supportive medium (such as agar combined with nutrients)

… the protein extracted from human cancer cells could stimulate the growth of blood vessels in experiments with chicken embryos and tumor cells growing in petri dishes.

—Tina Hesman

Unfortunately, most laboratories can diagnose tuberculosis with certainty, or exclude it, only by placing sputum in a petri dish and waiting to see if the bacterium grows …

—The New York Times

… they found that the compound, sulforaphane, fights cancer in petri dishes.

—Doug Levy

2

: something (such as a place or situation) that fosters development

Of course being there for your team tends to contaminate your team. Our radio studio is currently a petri dish of disease.

—Matt Heath

"We view universities as a community's most promising petri dish for innovation," said Abby Taubner …

—Alex Wittenberg

MTV's The Real World, which sends seven attractive young strangers to spend six months turning their luxury housing into a Petri dish of sexual, racial, and interpersonal tension, has been running since 1992.

—Francine Prose

Examples of petri dish in a Sentence

Recent Examples on the Web

That should absolutely change, says Anne Sharkey, a podiatrist in Cedar Park, Texas, who views shoes as mobile petri dishes of germs. —Angela Haupt, Time, 25 Aug. 2025

Han was accused of smuggling in filter paper containing plasmids on Sept. 23 and March 5 and petri dishes containg C. elegans with genetic modifications on Sept. 29, according to an information filed in court June 26. —Christina Hall, Freep.com, 19 Aug. 2025

Smallville was a petri dish for virtual sociality; rather than watching cells multiply, Park observed the agents gradually coalescing from individual nodes into a unified network. —Webb Wright, Scientific American, 18 Aug. 2025

King told the Statesman that non-moving water bodies can act like Petri dishes in the summer heat, allowing cyanobacteria numbers to explode under the right conditions. —Alex Music august 9, Idaho Statesman, 9 Aug. 2025

Word History

Etymology

Julius R. Petri †1921 German bacteriologist

First Known Use

1892, in the meaning defined at sense 1

Rhymes for petri dish

• cuttlefish
• jellyfish
• sablefish
• bluefish
• catfish
• codfish
• crawfish
• dogfish
• finfish
• flatfish
• goldfish
• groundfish

Kids Definition

Petri dish

noun

Pe·​tri dish

ˌpē-trē-

: a small shallow dish of thin glass or plastic with a loose cover used especially for cultures of bacteria

Medical Definition

petri dish

noun

pe·​tri dish

variants also Petri dish

ˈpē-trē- 

: a small shallow usually round dish of thin glass or plastic with a loose cover used especially for growing cells on a supportive medium (such as agar combined with nutrients)