Hesychius of Alexandria (flourished 5th century ad) was an author of the most important Greek lexicon known from antiquity, valued as a basic authority for the dialects and vocabularies of ancient inscriptions, poetic text, and the Greek Church Fathers.
Although nothing is known of his life, Hesychius indicated the comprehensive design of his lexicon in a letter prefacing the work. Entitled Synagōgē pasōn lexeōn kata stoicheion (“Alphabetical Collection of All Words”), the lexicon was based on other accessible specialized lexica dating to the 1st century bc, but Hesychius particularly borrowed from Diogenianus of Heraclea, a 2nd-century-ad language scholar from a Greek colony in what is now southern Italy. Hesychius, however, contributed original glosses interpreting Homeric proverbs, citations from other classical Greek authors, selections from different dialects, and a glossary illustrating the vocabulary of Cyril of Alexandria, the early 5th-century theological spokesman for Greek Orthodoxy. Hesychius’s introduction further stated that he included the sources of the rare words listed. The lexicon has been preserved only in a 15th-century abridgement, whose Venetian editor extensively interpolated and disfigured the original manuscript and deleted the sources of the entries, thus reducing the lexicon to a copious glossary. Nevertheless, enough of Hesychius’s work remains so that citations from Attic literature preserve the ancient readings for which easier synonyms were later substituted in other extant manuscripts of these writings. Two volumes (alpha to omicron) of a critical edition of Hesychius’s lexicon by K. Latte were published in 1953 and 1966, respectively.