Encomium

The plural of encomium is encomia, although OED says this is rare, preferring encomiums. See -um in Latin.

Encomium is a Latin word, meaning a eulogy, or 'formal expression of praise'. It is nearly always used in academic circles. As academics, particularly the older ones, are fond of the traditions of Latin, it is best, particularly when writing for the sort of teacher who was brought up knowing Latin, to use the form of the plural that Latin would use.

The Latin word encomium is the Latinised form - almost a transliteration - of the Greek noun ἐγκώμιον (enkomion), which means 'laudatory ode, eulogy, or panegyric'. The latter in turn is a compound of the prefix ἐν (en, in} and the noun κῶμος (komos), which means either 'revelling or merry-making' or 'a group of revellers or merry-makers'; the word was used, more particularly, of the procession which accompanied a victor in the games and celebrated his victory. It is also the root of the word 'comedy'

From the Greek κῶμος (komos) comes the Latin Comus, the name of a god of revelry in late Roman mythology. In John Milton's Masque of the same name Comus is a pagan god, the son of Bacchus and Circe, who accosts travellers and by means of magic potions changes their faces into those of wild animals and induces them 'to roll with pleasure in a sensual sty' (Comus, line 77). Milton (1608-1674) wrote Comus in 1634 to celebrate the Earl of Bridgewater's appointment as Lord President of Wales and the Marches, and the masque was performed before the Earl at Ludlow Castle in the same year.