di·ag·nos·tic
ˌdī-ig-ˈnä-stik 
-əg-
variants
or less commonly diagnostical
ˌdī-ig-ˈnä-sti-kəl
-əg-
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
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
Victoria Kusztos, ABC News, 2 Mar. 2026
Today, clinicians have access to better tools to identify subclinical disease, including certain blood biomarkers found in lab tests and additional diagnostic imaging, such as coronary artery calcium scoring, that can detect subtle heart disease and inflammation long before symptoms appear.
—Jia Shen, San Diego Union-Tribune, 25 Feb. 2026
Michelle Fox, CNBC, 2 Mar. 2026
Research indicates that asset-intensive industries are increasingly investing in connected diagnostics and performance analytics to improve maintenance decision-making and cost predictability.
—Daniel Fusch, USA Today, 27 Feb. 2026
See All Example Sentences for diagnostic
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Adjective
Norton also pointed to several emerging technologies that may help detect breast cancer earlier and lead to more effective treatment even in low-income areas, including digital pathology, diagnostic blood tests, and cancer-preventing vaccines.
—Victoria Kusztos, ABC News, 2 Mar. 2026
Today, clinicians have access to better tools to identify subclinical disease, including certain blood biomarkers found in lab tests and additional diagnostic imaging, such as coronary artery calcium scoring, that can detect subtle heart disease and inflammation long before symptoms appear.
—Jia Shen, San Diego Union-Tribune, 25 Feb. 2026
Noun
The deal, worth up to $23 billion, would bring Exact Science's colorectal cancer test Cologuard into Abbott's diagnostics portfolio.
—Michelle Fox, CNBC, 2 Mar. 2026
Research indicates that asset-intensive industries are increasingly investing in connected diagnostics and performance analytics to improve maintenance decision-making and cost predictability.
—Daniel Fusch, USA Today, 27 Feb. 2026
See All Example Sentences for diagnostic
Cite this Entry
“Diagnostic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diagnostic. Accessed 10 Mar. 2026.
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