διχοτομία

Forms

δῐχοτομῐ́ᾱ (dikhotomíā) f (genitive δῐχοτομῐ́ᾱς); first declension^[1]

Etymology

It is from Ancient Greek διχότομος (dikhótomos, “cut in two”) + -ία (-ía), an abstract noun from the adjective.^[1][2] The adjective joins δίχα (díkha, “in two, asunder”) and the stem of τέμνω (témnō, “to cut”).^[3]

Earliest recorded meaning

The first records are in Aristotle, who uses it both for the moon's half phases and for division into two parts, in nature and in logic.^[4][5][6]

Semantic evolution

In Aristotle the word already has two uses: in the biological works it names the logical division of a class into two subclasses, a method of classification he discusses at length, and in the Generation of Animals the plural names the moon's half phases, the points between new and full moon.^[5][4] Theophrastus uses that astronomical plural in his work on weather signs, and Geminus has it too.^[4][5]

Mathematicians made it a term of geometry: the bisection of a line, of a circle by its diameter or of an angle, and the point of bisection itself, the midpoint of a line or arc, in Euclid and Archimedes.^[4][5] Asclepiodotus' treatise on tactics uses it for the point where the two wings of an army part.^[5] In Christian writing Basil of Caesarea uses it figuratively for a separation.^[4]

English took it as dichotomy about 1600, from a Latinized form of the Greek word, first for a cutting in two or a division into two classes.^[3] In Modern Greek διχοτομία (dichotomía) is a learned revival of the ancient word, used for halving something and for a division of a whole into two radically different parts.^[7]

Timeline

• 4th century BC – Aristotle uses it for the moon's half phases and for logical division into two.^[5][4]
• 4th–3rd century BC – Theophrastus uses the plural of the moon's half phases in his work on weather signs.^[4]
• 3rd century BC – Euclid and Archimedes use it for the point that bisects a line.^[5][4]
• 1st century BC – Asclepiodotus uses it for the point dividing the wings of an army.^[5]
• 2nd century AD – Theon of Smyrna uses it for the bisection of a magnitude.^[5][4]
• 4th century AD – Basil of Caesarea uses it figuratively for a separation.^[4]
• About 1600 – English borrows a Latinized form of it as dichotomy.^[3]
• Modern times – Modern Greek revives it as a learned word for halving and for a division into two opposed parts.^[7]

Meanings

Noun

1. Division into two parts; in geometry, the bisection of a line, a circle or an angle.^[5][4]
2. The point of bisection, the midpoint of a line or arc.^[5][4]
3. (astronomy) A half phase of the moon, one of its quarters.^[5][4]
4. (logic) Division of a class into two, dichotomy.^[5][4]
5. (military) The point of division between the two wings of an army.^[5]
6. (figurative) A separation.^[4]

Related words

• διχότομος (dikhótomos)
• δίχα (díkha)
• τέμνω (témnō)
• English dichotomy

References

1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ Bailly, Anatole (2020), Dictionnaire grec-français, Bailly 2020 Hugo Chávez ed., ed. Gérard Gréco et al.
3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g h i j k l m n o Rodríguez Adrados, Francisco, et al., eds. (1980–), Diccionario Griego-Español, Madrid: CSIC, http://dge.cchs.csic.es/xdge
5. ^ a b c d e f g h i j k l m n Liddell, Henry George; Scott, Robert; Jones, Henry Stuart (1940), A Greek-English Lexicon, 9th ed., Oxford: Clarendon Press
6. ^ Keersmaekers, Alek (2021–2025), GLAUx: The Greek Language Automated corpus, https://github.com/alekkeersmaekers/glaux
7. ^ a b Ινστιτούτο Νεοελληνικών Σπουδών (Ίδρυμα Μανόλη Τριανταφυλλίδη) (1998), Λεξικό της κοινής νεοελληνικής, Thessaloniki: Aristotle University of Thessaloniki