diagnose

Etymology

It is a back-formation from English diagnosis,^{[2][3][4][5][6]} on the model of metamorphose and anastomose, which follow French verbs in -oser formed from nouns in -ose.^[2][3] Diagnosis is from New Latin diagnōsis,^[5][3] from Ancient Greek διάγνωσις (diágnōsis, “a discerning, distinguishing”), from διαγιγνώσκω (diagignṓskō, “to distinguish, discern”),^[2][3][7] from διά (diá, “apart, through”) and γιγνώσκω (gignṓskō, “to come to know, perceive”),^[7][4][2] from Proto-Indo-European *gnō- (“to know”), the root of know.^[3][4][7] Before the verb, English used diagnosticate, recorded by 1834.^[3]

Earliest recorded meaning

To identify a disease from its symptoms: 1861, in A. Wynter's Our Social Bees,^[2][3][5] though Merriam-Webster dates its first use to about 1859.^[8]

Semantic evolution

The noun diagnosis had been in English since 1681,^[5][3] and Ayto notes that its Greek source meant "knowing apart", the general sense of distinguishing having been applied in post-classical times to the medical examination that determines the nature of a disease.^[7] The verb kept that medical sense; from 1882 it was also used without an object, meaning to make a diagnosis.^[2] In the early 20th century the person examined could be its object.^[6] It is also used outside medicine, for working out the cause or nature of any problem.^[8][9]

Timeline

• 1681 – the noun diagnosis.^[5][3]
• 1834 – the earlier verb diagnosticate.^[3]
• c. 1859 – first known use, according to Merriam-Webster.^[8]
• 1861 – to identify a disease from its symptoms.^[2][3][5]
• 1882 – without an object, to make a diagnosis.^[2]
• early 20th century – to examine a person and find what is wrong.^[6]

Meanings

Verb

1. To identify a disease or condition from its symptoms or distinguishing signs: The doctor diagnosed measles.^[8][9][2]
2. To examine a person and find out what illness they have: She was diagnosed with asthma as a child.^[6][9]
3. To work out the cause or nature of a problem: The mechanic diagnosed a fault in the fuel pump.^[8][9]
4. To make a diagnosis.^[2][6]

Word family

• diagnosable
• undiagnosed
• misdiagnose
• underdiagnose

Related words

• diagnosis
• diagnostic
• diagnosticate
• know

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j k Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
6. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
7. ^ a b c d Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
8. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins