This is the 14534th most frequent Turkish word.
partimizi
"Our party" (possessive form of "party").
'Partimizi' is used as a possessive pronoun conjunction indicating 'our party' in the accusative case because it is the definite object being acted upon.
Bu akşam partimizi bahçede düzenliyoruz.
This evening, we are hosting our party in the garden.
Here, 'partimizi' again indicates 'our party' with a direct object function in an action where it is the object being influenced by the subject's decision.
Partimizi erken bitirmek zorunda kaldık çünkü hava bozuldu.
We had to end our party early because the weather deteriorated.
In this context, 'partimizi' describes 'our party' as the direct object of the perception action, carrying the accusative suffix.