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

Brown was subsequently put on a waiting list after her diagnosis to have the BCC removed. — Nicholas Rice, PEOPLE, 26 July 2026

Yet among women, Black women have the highest diagnosis rate of any racial or ethnic group of women. — Jallicia Jolly, Forbes.com, 26 July 2026

Despite the earlier drama, the four have since appeared publicly closer, especially as Kate and Charles faced their respective cancer diagnoses. — Allison Degrushe, StyleCaster, 26 July 2026

Any adult experiencing memory problems who receives a clinical evaluation and diagnosis of mild cognitive impairment would be a good candidate for the blood test. — Samantha Agate, Kansas City Star, 25 July 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