eccentricus

Forms

eccentricus (feminine eccentrica, neuter eccentricum); first/second-declension adjective^[1][2] Also spelled excentricus and encentricus.^[1][2][3]

Etymology

It is from Latin eccentrus (“off-centre”) + -icus.^[2][3] The Late Latin adjective ⟨eccentrus⟩, found in Chalcidius around AD 300, is borrowed from Ancient Greek ἔκκεντρος (ékkentros, “out of the centre”),^[2][3][1] from ἐκ (ek, “out of”) and κέντρον (kéntron, “centre”).^[2][4]

Earliest recorded meaning

Adelard of Bath has it of a planet's circle, which is eccentric with respect to the earth;^[3] the earliest dated instance in the DMLBS is in John of Salisbury's Entheticus.^[3][2]

Semantic evolution

It was a term of Ptolemaic astronomy.^[4] As an adjective it describes a circle or orbit whose centre is not the centre of the earth, and as a noun (understood circulus) it is such a circle:^[3][1] Sacrobosco defines it as any circle that divides the earth equally but has its centre outside the earth's, and Grosseteste explains that the sun's circle is called eccentric because its centre lies outside the earth's.^[3] Albert the Great discusses eccentrics and epicycles in his commentaries on Aristotle,^[1] and Roger Bacon reports that theologians argued about them.^[3]

English eccentric was first an astronomical term; the sense “odd person” dates from 1817.^[4]

Timeline

• c. 1160 – John of Salisbury, Entheticus.^[3][2]
• 13th century – Albert the Great, on eccentrics and epicycles.^[1][2]
• early 15th century – English eccentric, of an eccentric circle.^[4]

Meanings

Adjective

1. (astronomy, geometry) eccentric, having its centre away from the earth's centre.^[3][1][2][5]

Noun

1. (astronomy) An eccentric circle or orbit.^[3][1][2]

Related words

• centrum
• English eccentric

References

1. ^ a b c d e f g h Mittellateinisches Wörterbuch bis zum ausgehenden 13. Jahrhundert (1967–), Munich: C. H. Beck; Bayerische Akademie der Wissenschaften
2. ^ a b c d e f g h i j Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
3. ^ a b c d e f g h i j k 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 Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ Latinitatis medii aevi lexicon Bohemorum / Slovník středověké latiny v českých zemích (1977–), Prague: Academia; electronic version, Institute of Philosophy of the Czech Academy of Sciences