diagnostic

American  

[dahy-uhg-nos-tik] / ˌdaɪ əgˈnɒs tɪk /

adjective

1. of, relating to, or used in diagnosis.

2. serving to identify or characterize; being a precise indication.

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noun

diagnostics plural

1. diagnosis.

2. a symptom or characteristic of value in diagnosis.

3. Medicine/Medical. a device or substance used for the analysis or detection of diseases or other medical conditions.

4. Computers.

   1. a message output by a computer diagnosing an error in a computer program, computer system, or component device.

   2. a program or subroutine that produces such messages.

diagnostic British  

/ ˌdaɪəɡˈnɒstɪk /

adjective

1. of, relating to, or of value in diagnosis

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noun

1. med any symptom that provides evidence for making a specific diagnosis

2. a diagnosis

Other Word Forms

Derived Forms

• postdiagnostic
  adjective
• prediagnostic
  adjective
• diagnostically
  adverb

Inflected Forms

Nouns

• diagnostics
  plural

Etymology

Origin of diagnostic

1615–25; < Greek diagnōstikós, equivalent to diagnōst ( ós ) distinguished (akin to diágnōsis; see diagnosis) + -ikos -ic

Explanation

Anything diagnostic has to do with disease, especially figuring out which one a patient has. If your doctor wants to run diagnostic tests, then she isn't exactly sure what's wrong with you — so the tests will help diagnose you (figure out what's wrong). The TV show House is all about diagnostic tests: it features illnesses that are unusual and hard to determine. But anything diagnostic is trying to figure out what's wrong. A writing test could be called diagnostic if it's trying to determine how good or bad your writing skills are.

Example Sentences

See Examples For:

diagnostic diagnostics

And its pharmaceutical diagnostic arm logged revenue of $843 million, a 16% jump from last year.

From The Wall Street Journal ● Jul. 29, 2026

This strengthens the argument for diagnostic and treatment strategies tailored more closely to each individual.

From Science Daily ● Jul. 27, 2026

A recent report in the Journal of Periodontology predicts that technology such as AI, diagnostic saliva tests and sensor-based monitoring will allow for more early detection and individualized treatment.

From The Wall Street Journal ● Jul. 26, 2026

Brown said he was initially diagnosed with “bad food poisoning” but after multiple visits to urgent care and shedding 20 pounds, the health care team conducted a diagnostic fecal test and discovered Brown had cyclosporiasis.

From Los Angeles Times ● Jul. 14, 2026

“Perhaps a diagnostic hip x-ray would be in order.”

From "The Wednesday Wars" by Gary D. Schmidt

Meanwhile, its diagnostics division saw a 3% rise in sales on demand for immunodiagnostic and clinical chemistry products, Roche added.

From The Wall Street Journal ● Jul. 23, 2026

“AI-driven drug discovery, clinical development and diagnostics are beginning to improve productivity across the sector, while life science tools appear to be emerging from a multiyear destocking cycle.”

From MarketWatch ● Jul. 15, 2026

"Innovations in imaging hardware have the potential to transform diagnostics, and this study is an important step toward next-generation MRI technology," says Dr. Ebba Beller, a co-author of the paper at Rostock University Medical Center.

From Science Daily ● Jul. 10, 2026

The company, which connects buyers with third-party sellers, conducts background checks to vet vendors and rigorous diagnostics to ensure product quality, said Taylor Munguia, Reebelo’s chief commercial officer.

From The Wall Street Journal ● Jun. 21, 2026

I spent the last several days running full diagnostics on everything.

From "The Martian" by Andy Weir