διόπτρα
dioptra

Greek noun

Last edited: 2025-05-18
Primary meaning dioptra
Literal translation dioptra
Variants
διόπτρα dioptra
Edited by
dioptra astronomical instrument, artefact of astral science

The term dioptra is used for a broad class of instruments which one looks through.

Τὰ μὲν οὖν δωδεκατημόρια ἴσα ἐστὶ κατὰ τὸ μέγεθος· διόπτρᾳ γὰρ διῄρηται ὁ τῶν ζῳδίων κύκλος εἰς ιβʹ μέρη ἴσα.

‘Thus, the twelfth parts are equal in size: for the zodiac has been divided by means of the dioptra into 12 equal parts.’

— Geminus 1.4

Genre: astronomy
Date: 1st century BCE

Geminus. 1975. Géminos, Introduction aux Phénomènes, ed. G. Aujac. Paris: Les Belles Lettres. 1

Cite this entry
APA (7th)
Peeters, T. (2025). διόπτρα (Lemma #1108). The ZODIAC Glossary: A Cross-Cultural Glossary of Ancient Astral Science. https://zodiacglossary.github.io/lemma/1108/
Chicago (Author-Date)
Peeters, T. (2025). διόπτρα (Lemma #1108). The ZODIAC Glossary: A Cross-Cultural Glossary of Ancient Astral Science. https://zodiacglossary.github.io/lemma/1108/
MLA (9th)
Peeters, T. (2025). διόπτρα (Lemma #1108). The ZODIAC Glossary: A Cross-Cultural Glossary of Ancient Astral Science. https://zodiacglossary.github.io/lemma/1108/
Harvard
Peeters, T. (2025) διόπτρα (Lemma #1108), The ZODIAC Glossary: A Cross-Cultural Glossary of Ancient Astral Science. Available at: https://zodiacglossary.github.io/lemma/1108/ (Accessed: February 2, 2026).
BibTeX 
@misc{zodiac1108,
	note = {[Online; accessed 2026-02-02]},
	author = {Peeters, Thomas},
	year = {2025},
	title = {διόπτρα ({Lemma} #1108)},
	url = {https://zodiacglossary.github.io/lemma/1108/},
	howpublished = {https://zodiacglossary.github.io/lemma/1108/},
}