coenobia

The oldest layer is Greek κοινόβιον, koinobion, literally a common life. It joins κοινός, meaning common or shared, with βίος, meaning life. In late antique Christian usage, the word named a monastery where monks lived together under a rule. The idea was social before it was architectural.

That Greek term moved into Late Latin as coenobium, with the plural coenobia. In the 4th century CE, Pachomius in Egypt organized communal monasteries that made the term concrete in Christian history. His foundations, dated to the 320s and 330s, contrasted with the solitary life of hermits. A coenobium was the house of shared discipline.

Medieval Latin kept the word in learned and ecclesiastical writing, and English later borrowed the plural form coenobia. The borrowing remained rare and bookish, usually appearing in histories of monasticism or translations of church texts. Its learned spelling preserves the older oe, even where simpler forms later appeared. That visual archaism tells you the word arrived through scholarship.

In modern English, coenobia still means communal monasteries or monastic communities living under a common rule. It is not a household word, but it is precise. Where monastery is broad, coenobia points to the specifically communal model of religious life. The old Greek sense of shared life remains plainly visible.