[ 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.

Nearby words

  1. diagenetic,
  2. diageotropic,
  3. diageotropism,
  4. diaghilev,
  5. diaghilev, sergei pavlovich,
  6. diagnoses,
  7. diagnosis,
  8. diagnosis by exclusion,
  9. diagnostic,
  10. diagnostic diphtheria toxin

Origin of diagnose

First recorded in 1860–65; back formation from diagnosis

Related forms
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for undiagnosed

British Dictionary definitions for undiagnosed


/ (ˌʌndaɪəɡˈnəʊzd) /


(of a medical condition, a problem, etc) not having been identified


/ (ˈdaɪəɡˌnəʊz) /


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

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 undiagnosed



1861, back-formation from diagnosis. Related: Diagnosed; diagnosing.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for undiagnosed


[ dīəg-nōs′, -nōz′ ]


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

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.