Oikoclitic

In the oblique, the vowel of the oikoclitic singular masculine marker has been assimilated to the vowel of the Greek-derived nominative markers.

Source: wiktionary

Although there are some similarities between oikoclitic and xenoclitic classes - perhaps most noticeably the constant plural oblique -en (though with a variant -jen restricted to the oikoclitic classes), an inflection that is clearly indigenous - there are also striking differences.

Source: wiktionary

In the oikoclitic compartment, there are two distinct classes of vocalic and zero adjectives.

Source: wiktionary