encaenia
A festival held to mark the anniversary of the dedication of a church or temple; (especially), of the Temple at Jerusalem.
The annual commemoration service of founders and benefactors of Oxford University.
I am but just returned from two great shews that have been exhibited lately the review at Portsmouth and the encenia at Oxford.
Where it comes from
From Latin encaenia, from Ancient Greek (τὰ) ἐγκαίνια ((tà) enkaínia, “dedication festival”), from ἐν (en, “in”) + καινός (kainós, “new”).
Adapted from the Wiktionary entry encaenia (CC BY-SA 4.0).