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

In those five years, AlphaFold 2 and its successor AI models have become almost as fundamental and ubiquitous tools of biochemical research as microscopes, petri dishes, and pipettes. —Jeremy Kahn, Fortune, 28 Nov. 2025

Bolder clothes got her through the door at the legendary Blitz club and into its petri dish of weirdo creatives, including BodyMap’s Stevie Stewart, Stephen Jones, and Leigh Bowery. —Anna Cafolla, Vogue, 26 Nov. 2025

Although some initial research showed that ivermectin could stop cell cultures in a petri dish from getting infected with the coronavirus, the drug is not effective at treating the virus in humans, according to medicinal chemist Derek Lowe. —Ciara McCarthy, Fort Worth Star-Telegram, 28 Oct. 2025

The piece includes petri dishes the pair used to develop these plants — there are actually specimens developing under a grow light — as well as six video monitors simultaneously showing their process of collecting human samples and grafting plants. —Ray Mark Rinaldi, Denver Post, 20 Oct. 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)