diagnostic

1 of 2

adjective

di·​ag·​nos·​tic ˌdī-ig-ˈnä-stik How to pronounce diagnostic (audio)
-əg-
variants or less commonly diagnostical
1
a
: of, relating to, or used in diagnosis
a diagnostic tool
b
: using the methods of or yielding a diagnosis
diagnostic tests
2
: serving to distinguish or identify
a diagnostic feature
diagnostically adverb

diagnostic

2 of 2

noun

1
: the art or practice of diagnosis
often used in plural
2
: a distinguishing mark
diagnostician noun

Examples of diagnostic in a Sentence

Adjective Ultrasound is now widely used as a diagnostic tool. One important diagnostic feature of this condition is a mild rash. Noun the thesis that moral decline is the infallible diagnostic of a decadent society
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Results can be easily shared with a physician, who can then recommend diagnostic follow-ups and a personalized care plan. Sindhya Valloppillil, Forbes.com, 1 July 2025 These same-day surgery centers are more convenient and less expensive for patients by providing care—including diagnostic and preventive procedures—without the need for an overnight stay. Newsweek Rankings, MSNBC Newsweek, 30 June 2025
Noun
The Mayo Clinic in Rochester, NY, has initiated over 200 AI projects through its Center for Digital Health, integrating artificial intelligence into diagnostics and patient care. William Jones, USA Today, 1 July 2025 Big Contracts and Consolidation are Choking Pet Tech and Food Startups What was once a regional diagnostics and technology business has gone national, with industry giants like Mars, Zoetis, and IDEXX locking in long-term contracts with veterinary groups. Richard Kestenbaum, Forbes.com, 30 June 2025 See All Example Sentences for diagnostic

Word History

First Known Use

Adjective

1625, in the meaning defined at sense 1a

Noun

1625, in the meaning defined at sense 1

Time Traveler
The first known use of diagnostic was in 1625

Cite this Entry

“Diagnostic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diagnostic. Accessed 8 Jul. 2025.

Kids Definition

diagnostic

adjective
di·​ag·​nos·​tic
ˌdī-ig-ˈnäs-tik
: of, relating to, or used in diagnosis
a diagnostic test for heart disease

Medical Definition

diagnostic

1 of 2 adjective
di·​ag·​nos·​tic -ˈnäs-tik How to pronounce diagnostic (audio)
variants also diagnostical
1
: of, relating to, or used in diagnosis
2
: using the methods of or yielding a diagnosis
a diagnostic service
diagnostic properties
diagnostically adverb

diagnostic

2 of 2 noun
: the art or practice of diagnosis
often used in plural

More from Merriam-Webster on diagnostic

Last Updated: - Updated example sentences
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