"writing implement," late 13c., from Old French pene "quill pen; feather" (12c.) and directly from Latin penna "a feather, plume," in plural "a wing," in Late Latin, "a pen for writing," from Old Latin petna, pesna, from PIE *pet-na-, suffixed form of root *pet- "to rush; to fly" (see petition, n.).Latin penna and pinna "a feather, plume;" in plural "a wing;" also "a pinnacle; battlement" (see pin, n.) are treated as identical in Watkins, etc., but regarded as separate (but confused) Latin words by Tucker and others, who derive pinna from PIE *spei- "sharp point" (see spike, n.1) and see the "feather/wing" sense as secondary.In later French, this word means only "long feather of a bird," while the equivalent of English plume is used for "writing implement," the senses of the two words thus are reversed from the situation in English. Pen-and-ink (adj.) is attested from 1670s. Pen name is recorded from mid-19c.

"enclosure for animals," Old English penn, penne, "enclosure, pen, fold," of uncertain origin, perhaps related to Old English pinn "pin, peg" (see pin, n.) on notion of a bolted gate or else "structure made of pointed stakes."

slang, "prison," 1884, shortening of penitentiary; earlier use (1845) probably is a figurative extension of pen, n.2.

late 15c., from pen, n.. Related: Penned; penning.

"to enclose in a pen," c.1200, from Old English *pennian, from the source of pen, n.2. Related: Penned; penning.