Source : Webster's Revised Unabridged Dictionary (1913)

Sea poppy \Sea" pop"py\ (Bot.)
   The horn poppy. See under {Horn}.

Source : WordNet®

sea poppy
     n : yellow-flowered Eurasian glaucous herb naturalized in along
         sandy shores in eastern North America [syn: {horn poppy},
          {horned poppy}, {yellow horned poppy}, {Glaucium flavum}]