This is the 7268th most frequent German word.
geburtstagsparty
Birthday party.
The word 'Geburtstagsfeier' refers to the event organized to celebrate someone's birthday.
Ich freue mich auf die Geburtstagsfeier.
I am looking forward to the birthday party.
Here 'Geburtstagsfeier' indicates the individual occurrence of such an event one is attending or hosting.
Am Samstag kann ich nicht, denn ich habe eine Geburtstagsfeier.
I cannot on Saturday because I have a birthday party.
In this context 'Geburtstagsfeier' is used to describe a specific past event, highlighting its qualities.