This is the 390th most frequent German word.
unseren
"Unseren" is the accusative plural form of "unser," meaning "our" in English.
The word 'unseren' is in the accusative case, describing a masculine singular noun.
Wir lieben unseren Hund.
We love our dog.
Here, 'unseren' is used with the preposition 'für', which is always followed by the accusative case.
Das ist ein Geschenk für unseren Freund.
This is a gift for our friend.
'Unseren' modifies 'Plan', and the preposition 'über' triggers the accusative case here.