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

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Etymology

Origin of diagnostic

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

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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

Under its Better Together programme, external the health board is proposing changes to services in a range of areas - adult physical health, adult mental health, urgent care and some diagnostic services.

From BBC ● Nov. 3, 2026

For the first time, it has reported seeing some patients' conditions "deteriorating" while waiting for diagnostic scans and tests.

From BBC ● Nov. 1, 2026

This “suggests that factors related to cancer detection, screening, and diagnostic practices may contribute to some of the observed increases,” the University of Iowa study says.

From The Wall Street Journal ● Oct. 21, 2026

“When she was talking about some subject other than diagnostic testing, she was very unprepossessing, very disingenuous,” said Fortune magazine reporter Roger Parloff.

From Los Angeles Times ● Oct. 21, 2026

"I am now doing a diagnostic on the reactor. I am thinking that Johanssen is busy with the launching training. So perhaps I do this diagnostic for her."

From "The Martian" by Andy Weir

This will likely offset the Dutch health-technology company’s less impressive diagnostics and treatment sales growth, though these factors will be front of mind for investors, she adds.

From The Wall Street Journal ● Nov. 3, 2026

Idexx Laboratories reported strong growth in veterinary diagnostics, offsetting sluggish industry demand.

From Barron's ● Nov. 2, 2026

Roche said sales grew 7% when excluding currency changes, with increases in both its pharma and diagnostics divisions.

From The Wall Street Journal ● Oct. 22, 2026

Synnovis is diagnostics and pathology service which operates as a partnership between the hospitals and German company Synlab.

From BBC ● Oct. 16, 2026

I ran both through full diagnostics to confirm they were working correctly.

From "The Martian" by Andy Weir

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