Please tell me there’s a language out there that actually calls them “bird leaves.” Like how there’s a language where the word for green is “leaf blue.”

In Spanish the word for pen can also be for a feather.

Pluma

I think its more of a Latin America thing as textbooks prefer to use bolígrafo

In Spanish the word for pen can also be for a feather.

In English, too, with the word quill. Though the word now specifically means a pen made from a feather rather than a pen in general, and calling a feather that isn’t being used as a pen a quill is very archaic.

The spindle housing of a drill press is called a quill, oddly enough.