Suffixaufnahme is a grammatical device that occurs in some languages with case systems. It means that possessors are inflected for the case and number of the possessee as if they were adjectives. Here a few examples from Old Albic:
(1) mbar os nderos ‘the house of the man’
(2) mbaral orol nderorol ‘at/in the house of the man’
(3) mbaran oron nderoron ‘to the house of the man’
This can be nested:
(4) mbaran attoran nderomoloran ‘to the house of the father of the man’
In the last example, nderomolaran consists of the stem ndero ‘man’, a locative ending (marking the inalienable possession) -mol, a genitive ending -as agreeing with the genitive of atto ‘father’, and the allative ending -an ‘to’ agreeing with the ending of mbar ‘house’.
For more on suffixaufnahme, and natlangs showing this phenomenon, see Wikipedia: Suffixaufnahme.