1. 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.
2. A pen for writing made by sharpening and splitting the point or nib of the stock of a feather; as, history is the proper subject of his quill.
3. (Science: zoology) A spine of the hedgehog or porcupine. The pen of a squid. See Pen.
4. The plectrum with which musicians strike the strings of certain instruments. The tube of a musical instrument. He touched the tender stops of various quills. (milton)
5. Something having the form of a quill; as: The fold or plain of a ruff.
A hollow spindle. Quill bit, a bit for boring resembling the half of a reed split lengthways and having its end sharpened like a gouge. Quill driver, one who works with a pen; a writer; a clerk. Quill nib, a small quill pen made to be used with a holder.
Origin: Perhaps fr. F. Quille ninepin (see Kayless); but cf. Also G. Kiel a quill. MHG. Kil, and Ir. Cuille a quill.