Logeion is an open-access database of Latin and Ancient Greek dictionaries.^[1] Developed by Josh Goldenberg and Matt Shanahan in 2011, it is hosted by the University of Chicago. Apart from simultaneous search capabilities across different dictionaries and reference works, Logeion offers access to frequency and collocation data from the Perseus Project.

Having started out as an aggregator for Latin and Ancient Greek dictionaries, Logeion has implemented multiple new features in its development. These include:

• the integration of reference works on antiquity;
• frequency and collocation data from the Perseus Project;
• corpus examples, equally retrieved from the Perseus Project;
• references to relevant chapters in a number of (English-language) textbooks.

Furthermore, an iOS app was developed by Joshua Day in 2013. The app's second version, launched in 2018, is also available for Android devices.

As of November 2018, Logeion contains the following dictionaries.^[2]

• Autenrieth, G. (1891). A Homeric Dictionary for Schools and Colleges. New York: Harper and Brothers.
• Liddell, H. G., & Scott, R. (1889). An Intermediate Greek Lexicon. Oxford: Clarendon Press.
• Liddell, H. G., Scott, R., Jones, H. S., & McKenzie, R. (1940). A Greek-English Lexicon. Oxford: Clarendon Press.
• Slater, W. L. (1969). Lexicon to Pindar. Berlin: De Gruyter.

• Lewis, Ch. T., & Short, Ch. (1879). A Latin Dictionary. Oxford: Clarendon Press.
• Lewis, Ch. T. (1890). An Elementary Latin Dictionary. New York: American Book Company.

• Adrados, F. R., & Somolinos, J. R. (Eds.). Diccionario Griego-Español. Madrid: CSIC.
• Muñoz Delgado, L. (2001). Léxico de magia y religión en los papiros mágicos griegos. Madrid: CSIC.

• Babeliowsky, J. K. L., den Hengst, D., Holtland, W., van Lakwijk, W., Marcelis, J. Th. K., Pinkster, H., Smolenaars, J. J. L. (1975). Basiswoordenlijst Latijn. Den Haag: Staatsuitgeverij.
• Du Cange, Ch. et al. (1883-1887). Glossarium mediae et infimae latinitatis. Niort: L. Favre.
• Frieze, H. S. (1902). Vergil’s Aeneid Books I-XII, with an Introduction, Notes, and Vocabulary, revised by Walter Dennison. New York: American Book Company.
• Gaffiot, F. (1934). Dictionnaire Illustré Latin-Français. Paris: Hachette.
• Latham, R. E., Howlett, D. R., & Ashdowne, R. K. (1975-2013). The Dictionary of Medieval Latin from British Sources. London: British Academy.
• Pinkster, H. (Ed.) (2018). Woordenboek Latijn/Nederlands. Amsterdam: Amsterdam University Press.

• NA (n.d.). The Perseus Encyclopedia. Medford, MA: Tufts University.
• Peck, H. Th. (1898). Harper's Dictionary of Classical Antiquities. New York: Harper and Brothers.
• Smith, W. (1854). Dictionary of Greek and Roman Geography. London: Walter and Maberly; John Murray.
• Smith, W., Wayte, W., & Marindin, G. E. (1890). Dictionary of Greek and Roman Antiquities. London: John Murray.
• Stilwell, R. (1976). The Princeton Encyclopedia of Classical Sites. Princeton: Princeton University Press.

• List of academic databases and search engines

• Logeion