refractio

Forms

refrāctiō f (genitive refrāctiōnis); third declension^[1]

Etymology

It is formed from Latin refringō (“to break open, break off”) + -tiō, from the stem of its past participle ⟨refract-⟩.^[1][2][3]

Earliest recorded meaning

The earliest literal use the TLL records is in the Latin version of Hesychius' commentary on Leviticus (6th century AD), for the breaking off of the head of a bird offered in sacrifice, where it renders the Greek of the Septuagint.^[2][4]

Semantic evolution

In logic Boethius used it for a kind of conversion in which the order of the terms in the conclusion of a syllogism is reversed, rendering Greek κατὰ ἀνάκλασιν.^[2][5]

In Medieval Latin it became the word for the bending of a ray of light, refraction, as in Roger Bacon and Wycliffe, and it was also used figuratively.^[3] Köbler dates the optical sense from 1267, after Latham.^[4] English took refraction from it in the 1570s.^[6]

Timeline

• 6th century AD – The Latin Hesychius uses it of breaking off a sacrificial bird's head.^[2][4]
• 1267 – First British record of the medieval word for the refraction of light, after Latham.^[4]
• 1570s – English borrows it as refraction.^[6]

Meanings

Noun

1. The act of breaking off.^[2]
2. (logic) A conversion of a proposition in which the order of the terms is reversed.^[2][5]
3. (Medieval Latin) The bending of a ray of light, refraction.^[3][4][1]

Related words

• English refraction

Usage notes

A Greek–Latin glossary pairs it with ἀφήλωσις (aphḗlōsis).^[7]

References

1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
3. ^ a b c Latham, R. E., D. R. Howlett, R. K. Ashdowne, et al. (1975–2013), Dictionary of Medieval Latin from British Sources, London: British Academy / Oxford University Press
4. ^ a b c d e Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
5. ^ a b Conte, Gian Biagio; Pianezzola, Emilio; Ranucci, Giuliano (2010), il Latino: Vocabolario della lingua latina, 3rd ed., Florence: Le Monnier
6. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Goetz, Georg (1888–1923), Corpus glossariorum Latinorum, Leipzig: Teubner; vols. VI–VII Thesaurus glossarum emendatarum, digital ed. CGLO, Munich: Bayerische Akademie der Wissenschaften