The Collaborative International Dictionary of English v.0.48:

Poetic \Po*et"ic\, Poetical \Po*et"ic*al\, a. [L. po["e]ticus,
   Gr. ?: cf. F. po['e]tiquee.]
   1. Of or pertaining to poetry; suitable for poetry, or for
      writing poetry; as, poetic talent, theme, work,
      sentiments. --Shak.
      [1913 Webster]

   2. Expressed in metrical form; exhibiting the imaginative or
      the rhythmical quality of poetry; as, a poetical
      composition; poetical prose.
      [1913 Webster]

   Poetic license. See License, n., 4.
      [1913 Webster]

WordNet (r) 3.0 (2006):

poetic license
    n 1: license used by a writer or artist to heighten the effect
         of their work