Convivial is one of those words whose etymology I discovered in a slightly backward fashion. I learned the Latin root word first (in situ while studying Latin) and then the etymology of the Latin word before I even recognised the English cognate. This is possibly one of the best ways to learn the etymology of English words as the roots stick in one’s head far more firmly than if one were to learn it the other way round.
In modern English, convivial is an adjective usually used in reference to a person who is fond of, or regularly occupied with, hosting parties or company. The origin of convivial is the Latin word convivium meaning “party.” Convivium is itself a compound word in Latin. Its two elements are con (from com) meaning “with,” and vivere “to live.” Convivium means “to live with.” This brings to mind a more informal term for party: a “get-together.”
Thus convivial now has a connotation of “living with” (or “inviting people to live with one,” in the case of a convivial host) instead of simply “fond of, or occupied with, hosting.”
The title “Convivial: An English Word with an Elvish Meaning” immerged in my mind when I first learned the etymology of convivial. The word reminded me of the welcoming generosity of J.R.R. Tolkien’s Rivendell in The Hobbit and The Lord of the Rings. Perhaps hospitality is a more accurate word for the atmosphere of Rivendell, but hospitality does not have the same connotation as convivial in its Latin root. Hospitality comes from the Latin hospes meaning both “guest” and “host” and has no sense of “living with” as it refers more to hosting in a general sense.