pentagonum

Forms

pentagōnum n (genitive pentagōnī); second declension^[1] Also written pentagōnon, in the Greek form.^[2]

Etymology

It is borrowed from Ancient Greek πεντάγωνον (pentágōnon, “pentagon”),^[1][3][4] the neuter of the adjective πεντάγωνος (pentágōnos, “five-angled”), from πέντε (pénte, “five”) and γωνία (gōnía, “angle, corner”).^[5][3]

Earliest recorded meaning

Köbler and Gaffiot cite it as a term of geometry, a pentagon, from the Roman land surveyors (the Gromatici).^[3][2] Pseudo-Apuleius (end of the 4th century AD) uses it as a name of the cinquefoil, pentaphyllon.^[2][3]

Semantic evolution

Medieval scholars used it in geometry and optics: the Polish dictionary records the adjective pentagonus and the noun for a five-angled figure, in Witelo's Perspectiva among others.^[6] English pentagon (1560s) comes from French pentagone or directly from the Late Latin word.^[5]

Timeline

• end of the 4th century AD – Pseudo-Apuleius uses it as a name of the cinquefoil.^[2][3]
• 1560s – English borrows pentagon from French or from Late Latin.^[5]

Meanings

Noun

1. (geometry) A pentagon.^[2][1]
2. (botany) Cinquefoil, pentaphyllon.^[2][1]

Related words

• English pentagon

References

1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Gaffiot, Félix (2016), Dictionnaire latin-français, new ed. by Gérard Gréco et al. (Gaffiot 2016), online ed.
3. ^ a b c d e Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
4. ^ Conte, Gian Biagio; Pianezzola, Emilio; Ranucci, Giuliano (2010), il Latino: Vocabolario della lingua latina, 3rd ed., Florence: Le Monnier
5. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ Lexicon mediae et infimae Latinitatis Polonorum (1953–), Kraków: Instytut Języka Polskiego PAN; electronic ed. elexicon.scriptores.pl