This is the 6621st most frequent Turkish word.
aybüke
"Aybüke" is a Turkish feminine name meaning "moon-like princess."
In this sentence, 'Aybüke' is used as a proper noun referring to the person's name.
Aybüke, sevdiğim kitapları bana hediye etti.
Aybüke gifted me the books I love.
Here, 'Aybüke' signifies the subject of the sentence whose birthday is being celebrated, also a proper noun.
Bugün Aybüke'nin doğum gününü kutlayacağız.
Today, we will celebrate Aybüke's birthday.
In this context, 'Aybüke' is again a proper noun used to describe the person's characteristic.