Source : Webster's Revised Unabridged Dictionary (1913)

Pen \Pen\, v. t. [imp. & p. p. {Penned}; p. pr. & vb. n.
   {Penning}.]
   To write; to compose and commit to paper; to indite; to
   compose; as, to pen a sonnet. ``A prayer elaborately
   penned.'' --Milton.

Pen \Pen\, v. t. [imp. & p. p. {Penned}or {Pent} (?); p. pr. &
   vb. n. {Penning}.] [OE. pennen, AS. pennan in on-pennan to
   unfasten, prob. from the same source as pin, and orig.
   meaning, to fasten with a peg.See {Pin}, n. & v.]
   To shut up, as in a pen or cage; to confine in a small
   inclosure or narrow space; to coop up, or shut in; to
   inclose. ``Away with her, and pen her up.'' --Shak.

         Watching where shepherds pen their flocks at eve.
                                                  --Milton.

Source : WordNet®

pen
     v : produce a literary work; "She composed a poem"; "He wrote
         four novels" [syn: {write}, {compose}, {indite}]
     [also: {pent}, {penning}, {penned}]

pen
     n 1: a writing implement with a point from which ink flows
     2: an enclosure for confining livestock
     3: a portable enclosure in which babies may be left to play
        [syn: {playpen}]
     4: a correctional institution for those convicted of major
        crimes [syn: {penitentiary}]
     5: female swan
     [also: {pent}, {penning}, {penned}]

penning
     n : the act of creating written works; "writing was a form of
         therapy for him"; "it was a matter of disputed
         authorship" [syn: {writing}, {authorship}, {composition}]

penning
     See {pen}