The Collaborative International Dictionary of English v.0.48:

Pierian \Pi*e"ri*an\, a. [L. Pierius, from Mount Pierus, in
   Thessaly, sacred to the Muses.]
   Of or pertaining to Pierides or Muses.
   [1913 Webster]

         Drink deep, or taste not the Pierian spring. --Pope.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "Pierian":
   Alcaic, Anacreontic, Castalian, Homeric, Hudibrastic, Pindaric,
   Theocritean, bardic, bucolic, didactic, dithyrambic, dramatic,
   eclogic, elegiac, epic, heroic, idyllic, mock-heroic, narrative,
   pastoral, poetic, poetico-mystical, poetico-mythological,
   poetico-philosophic, poetlike, rhapsodic, runic, sapphic,
   skaldic