sea dragon

noun8

1. •
   Various sea animals that are likened to dragons.
2. •
   Certain fish.
3. •
   leafy sea dragon (Phycodurus eques)
4. •
   weedy sea dragon (Phyllopteryx taeniolatus)
5. •
   ruby sea dragon (Phyllopteryx dewysea)
6. •
   A blue sea dragon, a sea slug of species Glaucus atlanticus.
7. •
   (UK, old-fashioned) An ichthyosaur (dinosaur-age delphine marine reptile)
8. •
   A type of dragon that inhabits oceans.

   • In the Gentleman's Magazine for the year 1749, we have an account of a sea-dragon which was said to be taken between Orford and Southwould, on the coast of Suffolk[.] — 1810