• synonyms


[ 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.


Medical Terms You Didn’t Know ExistedRead more in this article about some frequently asked questions and fun facts related to our definitions.


interpretation, investigation, examination, analysis, conclusion, opinion, summary, pronouncement, scrutiny

Nearby words

diageotropism, diaghilev, diaghilev, sergei pavlovich, diagnose, diagnoses, diagnosis, diagnosis by exclusion, diagnostic, diagnostic diphtheria toxin, diagnostic specificity, diagnostic ultrasound

Origin of diagnosis

1675–85; < New Latin < Greek diágnōsis a distinguishing. See dia-, -gnosis
Related formspre·di·ag·no·sis, noun, plural pre·di·ag·no·ses.
Can be confuseddiagnosis prognosis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diagnosis

British Dictionary definitions for diagnosis


/ (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

Word Origin and History for diagnosis



1680s, medical Latin application of Greek diagnosis "a discerning, distinguishing," from stem of diagignoskein "discern, distinguish," literally "to know thoroughly," from dia- "apart" (see dia-) + gignoskein "to learn" (see gnostic).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for diagnosis


[ 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 diagnosis


[ 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.