Emily Dickinson Lexicon

PEN, n.¹ [L. penna; Sax. pinn; D. pen; It. penna, a feather, a pen, and a top; W. pen, top, summit, head; Ir. beann, beinn, written also ben. The Celtic nations called the peak of a mountain, ben or pen. Hence the name Apennine, applied to the mountains of Italy. It may belong to the same root as L. pinna, a fin, that is a shoot or point.]

1. An instrument used for writing, usually made of the quill of some large fowl, but it may be of any other material.
2. A feather; a wing. [Not used.] – Spenser.