diagnose

verb

di·​ag·​nose ˈdī-ig-ˌnōs How to pronounce diagnose (audio)
-ˌnōz,
ˌdī-ig-ˈnōs How to pronounce diagnose (audio)
-ˈnōz,
-əg-
diagnosed; diagnosing

transitive verb

1
a
: to recognize (something, such as a disease) by signs and symptoms
The other method of diagnosing gallstones is through an ultrasound examination, which has the advantages of being simple, safe and quick.G. Timothy Johnson
Pulmonary embolus was diagnosed in two of the actively treated patients …Richard D. Sautter et al.
b
: to recognize a disease or condition in
The physicist and cosmologist was diagnosed with Lou Gehrig's disease when he was a 21-year-old student at Cambridge University.Maria Cheng
2
: to analyze the cause or nature of
The mechanic diagnosed the problem with the engine.

intransitive verb

: to identify a disease from its signs and symptoms : to make a diagnosis
diagnosable adjective
or diagnoseable

Examples of diagnose in a Sentence

The test is used to help in diagnosing heart disease. Thousands of new cases have been diagnosed in the past year. The doctor was unable to diagnose the skin condition. a new doctor with little experience diagnosing patients The mechanic was unable to diagnose the problem.
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.
She was diagnosed with ovarian cancer two years later. Toria Sheffield, PEOPLE, 18 Oct. 2025 King Charles' Cancer Diagnosis Harry's approach seemed to hit a turning point in February 2024 after King Charles announced he had been diagnosed with cancer. Jack Royston, MSNBC Newsweek, 18 Oct. 2025 That's when Hausman, with an infant to care for, was diagnosed with stage 4 metastatic melanoma. Madeline Mitchell, USA Today, 18 Oct. 2025 Since then, concerns have resurfaced and grown after a beloved teacher died a year ago and another teacher was diagnosed with breast cancer late last year. Laura Bauer, Kansas City Star, 17 Oct. 2025 See All Example Sentences for diagnose

Word History

Etymology

back-formation from diagnosis

First Known Use

circa 1841, in the meaning defined at transitive sense 1a

Time Traveler
The first known use of diagnose was circa 1841

Browse Nearby Words

Cite this Entry

“Diagnose.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diagnose. Accessed 20 Oct. 2025.

Kids Definition

diagnose

verb
di·​ag·​nose ˈdī-ig-ˌnōs How to pronounce diagnose (audio) -ˌnōz How to pronounce diagnose (audio)
ˌdī-ig-ˈnōs,
-ˈnōz
diagnosed; diagnosing
: to recognize by signs and symptoms : make a diagnosis
diagnose a disease
diagnose a play in football

Medical Definition

diagnose

verb
di·​ag·​nose ˈdī-ig-ˌnōs How to pronounce diagnose (audio) -ˌnōz How to pronounce diagnose (audio)
ˌdī-ig-ˈ,
-əg-
diagnosed; diagnosing

transitive verb

1
: to recognize (as a disease) by signs and symptoms
2
: to diagnose a disease or condition in
diagnosed the patient
diagnosable adjective

More from Merriam-Webster on diagnose

Last Updated: - Updated example sentences
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