hexagonal

Etymology

It is formed from English hexagon + -al.^{[2][3][4][5][6]} Hexagon, recorded a year earlier, in 1570,^[2] is from Late Latin hexagōnum,^[2][3][7] from Ancient Greek ἑξάγωνον (hexágōnon), the neuter of ἑξάγωνος (hexágōnos, “six-cornered”),^[2][3] from ἕξ (héx, “six”) and -γωνος (-gōnos, “angled”), from the stem of γωνία (gōnía, “angle”).^[2][7] Etymonline traces the Greek noun to Proto-Indo-European *genu- (“knee; angle”).^[3]

Earliest recorded meaning

Of the shape of a hexagon, having six sides and six angles: 1571, in Thomas Digges's part of Leonard Digges's Pantometria.^[2][8] Etymonline dates it to the 1570s^[3] and Dictionary.com to 1565–75.^[5]

Semantic evolution

From plane figures the word was extended to solids whose cross-section is a hexagon, first in 1646 in Sir Thomas Browne's Pseudodoxia Epidemica;^[2] Johnson (1755) defined it as "having six sides or corners" and quoted Browne and Ray on the six-cornered shapes of crystals.^[6] In mathematics, hexagonal numbers (1, 6, 15, 28…) are recorded from 1728, in Chambers's Cyclopaedia, and hexagonal as a noun for such a number from 1796.^[2] In crystallography it has named, since 1837 in James Dwight Dana's Mineralogy, one of the principal crystal systems, with three equal axes in one plane at 60° and a fourth at right angles to them.^[2][9]

Timeline

• 1571 – having six sides and six angles.^[2][8]
• 1646 – of a solid, having a hexagon as its section or base.^[2]
• 1728 – hexagonal numbers.^[2]
• 1796 – noun, a hexagonal number.^[2]
• 1837 – in crystallography, of the hexagonal crystal system.^[2]

Meanings

Adjective

1. Having six sides and six angles; shaped like a hexagon: The garden path was laid with hexagonal tiles.^[9][8][10]
2. Of a solid: having a hexagon as its cross-section or base.^[8][2][10]
3. Divided into hexagons.^[8]
4. (crystallography) Of or belonging to the crystal system with three equal axes in one plane, set at 60° to one another, and a fourth axis of different length at right angles to them.^{[9][8][2][10]}
5. (mathematics) Of the series of polygonal numbers 1, 6, 15, 28, 45 and so on.^[2]

Word family

• hexagonally
• pseudohexagonal
• subhexagonal

Related words

• hexagon
• polygon
• pentagonal
• octagonal
• diagonal
• knee

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ 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
3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
7. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ a b c The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin