geometer

Etymology

It is inherited from Middle English gemeter,^[2] borrowed from Late Latin geōmeter,^[3][2] a variant of Latin geōmetrēs, also geōmetra (“land-measurer, geometrician”),^[3][4][5][6] which is from Ancient Greek γεωμέτρης (geōmétrēs, “land-measurer”),^[3][4][6] from γεω- (geō-), the combining form for earth, and μετρέω (metréō, “to measure”), from μέτρον (métron, “measure”).^[3][6] Merriam-Webster Unabridged also allows Middle French geometre as a source.^[7] The word is widespread in Europe: compare French géomètre, Italian geometra and German Geometer.^[3] The name of the caterpillar follows the genus name New Latin Geometra.^[3]

Earliest recorded meaning

An expert in geometry: the OED's first record is Trevisa's translation of De Regimine Principum, in a manuscript of about 1450, composed perhaps before 1402.^[3] Dictionary.com dates the word to 1375–1425,^[2] and Etymonline to the late 15th century.^[4]

Semantic evolution

Although the Greek word meant a land-measurer, English recorded the mathematical sense first, and the literal one only from 1773, in a letter by De Brahm; that use is chiefly American and now mostly historical.^[3][5] A rare use of 1635 perhaps meant an exciseman or an inspector of weights and measures.^[3] Johnson (1755) gives only "one skilled in geometry; a geometrician", quoting Watts.^[8] From 1817, in Kirby and Spence's Introduction to Entomology, it was also the caterpillar of a geometrid moth, which travels by looping its back in an arch.^[3] Merriam-Webster Unabridged extends the name to the moth itself.^[7]

Timeline

• c. 1450 – an expert in geometry.^[3]
• 1635 – perhaps an exciseman or an inspector of weights and measures (rare).^[3]
• 1773 – a person who measures land; a surveyor.^[3]
• 1817 – the caterpillar of a geometrid moth.^[3]

Meanings

Noun

1. A specialist in geometry: The young geometer spent a decade on the problem of curved surfaces.^[7][9][3]
2. A moth of the family Geometridae, or its larva; a looper.^[7][3][5]
3. (chiefly US, historical) A land surveyor.^[3][5]

Related words

• geographer
• geologist
• geometry
• geometrician
• geometrid

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
3. ^ a b c d e f g h i j k l m n o p q Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ Collins English Dictionary (2023), Glasgow: HarperCollins