diagnosis

noun

di·​ag·​no·​sis ˌdī-ig-ˈnō-səs 

-əg-

plural diagnoses ˌdī-ig-ˈnō-ˌsēz 

-əg-

1

a

: the art or act of identifying a disease from its signs and symptoms

b

: the decision reached by diagnosis

the doctor's diagnosis

2

a

: investigation or analysis of the cause or nature of a condition, situation, or problem

diagnosis of engine trouble

b

: a statement or conclusion from such an analysis

3

biology : a concise technical description of a taxon

Synonyms of diagnosis

• decision
• opinion
• verdict
• conclusion
• determination

Examples of diagnosis in a Sentence

The unusual combination of symptoms made accurate diagnosis difficult.

She is an expert in the diagnosis and treatment of eye diseases.

The diagnosis was a mild concussion.

His doctor made an initial diagnosis of pneumonia.

The committee published its diagnosis of the problems affecting urban schools.

Recent Examples on the Web

In that time, Sezalory had three kids, lost a brother and navigated her mother’s cancer diagnosis, all of which brought a new perspective. — Hilary Milnes, Vogue, 10 Aug. 2026

Hunter Biden said the diagnosis had been tough on the family. — CBS News, 9 Aug. 2026

Gusching underwent testing and ultimately received the same diagnosis. — Toria Sheffield, PEOPLE, 9 Aug. 2026

Heming Willis, 50, has since become an advocate for dementia awareness and caregiving while navigating her husband's frontotemporal dementia diagnosis. — Charlie Carballo, USA Today, 8 Aug. 2026

Word History

Etymology

New Latin, from Greek diagnōsis, from diagignōskein to distinguish, from dia- + gignōskein to know — more at know

First Known Use

1634, in the meaning defined at sense 1a

Phrases Containing diagnosis

• diagnosis related group
• differential diagnosis

Rhymes for diagnosis

• cirrhosis
• fibrosis
• gliosis
• hypnosis
• ichthyosis
• ketosis
• kurtosis
• lordosis
• meiosis
• miosis
• mitosis
• mycosis

Kids Definition

diagnosis

noun

di·​ag·​no·​sis ˌdī-ig-ˈnō-səs 

plural diagnoses -ˈnō-ˌsēz 

1

a

: the art or act of identifying a disease from its signs and symptoms

b

: the decision reached by diagnosis

2

a

: a careful study of something especially to determine its nature or importance

b

: the conclusion reached after a study or examination

Medical Definition

diagnosis

noun

di·​ag·​no·​sis ˌdī-ig-ˈnō-səs, -əg- 

plural diagnoses -ˌsēz 

1

a

: the art or act of identifying a disease from its signs and symptoms

b

: the decision reached by diagnosis

a diagnosis of pneumonia

2

: a concise technical description of a taxon