When we first met Latin masculine nouns of the 2nd declension, we noticed a good many (like circus, focus, and stimulus) that have come into English without any change in form. There are extremely few unchanged derivatives from the Greek -ος declension, though the English word cosmos (“universe”) is very close to its Greek etymon, κοςμος. This is only because the noun κοςμος was not used as a Latin loan-word. When the Romans borrowed nouns of this type, they consistently adapted the ending to the Latin 2nd declension -us, and made other standard changes in spelling:
|G||χορος||khoros||“dance,” “chorus”||> L||chorus|
|ἰσθμος||isthmos||“neck of land”||isthmus
|Οὐρανος||Ouranos||“Sky” [a god]||Uranus|
In the English derivatives hymn and throne, we can recognize common patterns of Anglicizing Latin words that we first met in Part I, §14.
Here are some useful 2nd declension Greek nouns in -ος:
Most of the compound derivatives—words with endings like -logy, -graphy, and -phobia —will be explained in the next chapter. Notice the English adjectives dactylic, cyclic, ophthalmic, topic, and chronic; these are all regular derivatives from Greek forms in -ικος. (English cyclical and topical show the extra Latin suffix.)