LSJ
ίδος, ἡ, a period of a thousand years, title of a work by Asinius Quadratus, Suid. s.v. Κοδρᾶτος (cf. χιλιαρχία III, χιλιάς II).
festival held after an interval of a thousand years, Hierocl. Facet. 62.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
[χῑ], ίδος, ἡ, Zeit von tausend Jahren, Suid., fem. zu χιλιέτηρος.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)