[ dahy-uh g-nohs, -nohz, dahy-uh g-nohs, -nohz ]
/ ˈdaɪ əgˌnoʊs, -ˌnoʊz, ˌdaɪ əgˈnoʊs, -ˈnoʊz /

verb (used with object), di·ag·nosed, di·ag·nos·ing.

to determine the identity of (a disease, illness, etc.) by a medical examination: The doctor diagnosed the illness as influenza.
to ascertain the cause or nature of (a disorder, malfunction, problem, etc.) from the symptoms: The mechanic diagnosed the trouble that caused the engine knock.
to classify or determine on the basis of scientific examination.

verb (used without object), di·ag·nosed, di·ag·nos·ing.

to make a diagnosis.

Origin of diagnose

First recorded in 1860–65; back formation from diagnosis

Related forms

Definition for diagnoses (2 of 2)


[ dahy-uh g-noh-sis ]
/ ˌdaɪ əgˈnoʊ sɪs /

noun, plural di·ag·no·ses [dahy-uh g-noh-seez] /ˌdaɪ əgˈnoʊ siz/.

  1. the process of determining by examination the nature and circumstances of a diseased condition.
  2. the decision reached from such an examination. Abbreviation: Dx
Biology. scientific determination; a description that classifies a group or taxon precisely.
a determining or analysis of the cause or nature of a problem or situation.
an answer or solution to a problematic situation.

Origin of diagnosis

1675–85; < New Latin < Greek diágnōsis a distinguishing. See dia-, -gnosis

Related forms

pre·di·ag·no·sis, noun, plural pre·di·ag·no·ses.

Can be confused

diagnosis prognosis
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diagnoses

British Dictionary definitions for diagnoses (1 of 2)


/ (ˈdaɪəɡˌnəʊz) /


to determine or distinguish by diagnosis
(tr) to examine (a person or thing), as for a disease

Derived Forms

diagnosable, adjective

British Dictionary definitions for diagnoses (2 of 2)


/ (ˌdaɪəɡˈnəʊsɪs) /

noun plural -ses (-siːz)

  1. the identification of diseases by the examination of symptoms and signs and by other investigations
  2. an opinion or conclusion so reached
  1. thorough analysis of facts or problems in order to gain understanding and aid future planning
  2. an opinion or conclusion reached through such analysis
a detailed description of an organism, esp a plant, for the purpose of classification

Word Origin for diagnosis

C17: New Latin, from Greek: a distinguishing, from diagignōskein to distinguish, from gignōskein to perceive, know
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for diagnoses (1 of 2)


[ dīəg-nōs′, -nōz′ ]


To distinguish or identify a disease by diagnosis.
To identify a person as having a particular disease or condition by diagnosis.

Medicine definitions for diagnoses (2 of 2)


[ dī′əg-nōsĭs ]

n. pl. di•ag•no•ses (-sēz)

The act or process of identifying or determining the nature and cause of a disease or injury through evaluation of patient history, examination, and review of laboratory data.
The opinion derived from such an evaluation.
A brief description of the distinguishing characteristics of an organism, as for taxonomic classification.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for diagnoses


[ dī′əg-nōsĭs ]

Plural diagnoses (dī′əg-nōsēz)

The identification by a medical provider of a condition, disease, or injury made by evaluating the symptoms and signs presented by a patient.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.