digon

English

WOTD – 11 February 2022

Etymology

PIE word *dwóh₁

PIE word *ǵónu

A digon with an internal area (the green portion) can be depicted on the surface of a sphere if its vertices are antipodal (on opposide sides of the sphere). On a flat surface, a digon would look like a line.

From di- (prefix meaning ‘two’) +‎ -gon (suffix forming the names of plane figures containing a given number of angles).

Pronunciation

• (Received Pronunciation) IPA^(key): /ˈdaɪɡən/, /ˈdaɪˌɡɒn/

• Audio (Southern England):

  (file)

• (General American) IPA^(key): /ˈdaɪɡən/, /ˈdaɪˌɡɑn/
• Hyphenation: di‧gon

Noun

digon (plural digons)

1. (geometry) A polygon having two edges and two vertices.

   Synonyms: biangle, bigon, (less common) diangle

   • 2013, Brent Davis, Moshe Renert, chapter 6, in The Math Teachers Know: Profound Understanding of Emergent Mathematics, New York, N.Y., Abingdon, Oxfordshire: Routledge, →ISBN, page 102:

     They [the students] also came upon new and unusual mathematical figures: the digon, a two-sided polygon on a spherical space, and the apeirogon, an open polygon with infinitely many sides  […]. All these discoveries brought up even more questions. Is a circle a polygon? What makes an octagon an octagon – its eight vertices, its eight sides, or both? Can a polygon cross itself? Does a polygon need to be closed?

2. (graph theory)
   1. A pair of parallel undirected edges in a multigraph.
   2. A pair of antiparallel edges in a directed graph.

Coordinate terms

• monogon · digon (biangle · bigon) · trigon (triangle) · tetragon (quadrilateral) · pentagon · hexagon · heptagon (septagon) · octagon · nonagon (enneagon) · decagon · undecagon · dodecagon · see also Category:English terms suffixed with -gon

Derived terms

• digonal

Translations

polygon having two edges and two vertices

Basque: digono Belarusian: двухвугольнік (dvuxvuhólʹnik) Bengali: দ্বিভুজ (bn) (dibhuj) Chinese: Mandarin: 二角形 (èrjiǎoxíng) Dutch: tweehoek (nl) m Esperanto: dulatero Finnish: kaksikulmio French: digone (fr) m German: Kugelzweieck n, sphärisches Zweieck n, Zweieck n, Kugelzweiseit m, Zwickel (de) m Hindi: डाइगोन (ḍāigon) Hungarian: kétszög Icelandic: tvíhyrningur m Interlingua: fuso Japanese: 二角形 (にかくかた, nikakukata) Korean: 이각형 (igakhyeong) Kurdish: Central Kurdish: دوولا (dûla) Lao: ຮູບສອງແຈ (hūp sǭng chǣ) Macedonian: двоаголник m (dvoagolnik) Norwegian: Bokmål: sfærisk tokant Polish: dwukąt m Russian: двуугольник (ru) m (dvuugolʹnik) Slovene: dvókótnik Spanish: dígono m Thai: รูปสองเหลี่ยม Ukrainian: дигон (dyhon), двокутник (dvokutnyk)

pair of parallel undirected edges in a multigraph

pair of antiparallel edges in a directed graph

Further reading

• digon on Wikipedia.Wikipedia

Anagrams

• Gondi, doing, doïng, Godin, ODing, Diong, OD'ing, dingo

Esperanto

Noun

digon

1. accusative singular of digo

French

Pronunciation

• Audio:

  (file)

Noun

digon m (plural digons)

1. digon

Welsh

Etymology

Deverbal from digoni (“to be able, to suffice”).

Pronunciation

• (North Wales) IPA^(key): /ˈdɪɡɔn/
• (South Wales) IPA^(key): /ˈdiːɡɔn/, /ˈdɪɡɔn/

Noun

digon m (uncountable)

1. enough, plenty, a sufficient amount

Derived terms

• digonol (“adequate”)

Adverb

digon

1. enough, sufficient

Mutation

Welsh mutation
radical	soft	nasal	aspirate
digon	ddigon	nigon	unchanged
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.

References

• R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke et al., editors (1950–present), “digon”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies