quill

n. 1 (in full quill-feather) large feather in a wing or tail. 2 hollow stem of this. 3 (in full quill pen) pen made of a quill. 4 (usu. In pl.) Porcupine's spine. [probably low german quiele]

n. One of the large feathers of a bird's wing, or one of the rectrices of the tail; also, the stock of such a feather.