"writing implement," c.1300, from O.Fr. penne "quill pen, feather," from L. penna "feather," from PIE *petna-, suffixed form of base *pet- "to rush, fly" (see petition
). From the same base comes suffixed form *petra-, source of Skt. patram "wing, feather," Gk. pteron "wing,"
O.C.S. pero "pen," O.N. fjöðr, O.E. feðer (see feather
). In later Fr., this word means only "long feather of a bird," while the equivalent of Eng. plume is used for "writing implement," the senses of the two words thus reversed from what they are in English. The verb is 1490, from the noun. Pen-pal first recorded 1938, gradually replacing earlier pen-friend (1933). Pen-and-ink (adj.) is attested from 1676.
"enclosure for animals," O.E. penn, penne, "enclosure," perhaps related to O.E. pinn "pin, peg" (see pin
) on notion of a bolted gate or else "structure made of pointed stakes." The verb, "to enclose in a pen" is attested from c.1200. Slang noun meaning "prison" (1884) is shortening
of penitentiary (q.v.), but earlier use (1845) is probably a fig. extension of this word.
Brythonic for "head;" common in place names in Cornwall and Wales (e.g. Penzance, see also Pendragon).