plesiosaurus
noun
ple·si·o·sau·rus
ˌplēsēəˈsȯrəs
1
capitalized : a genus of marine reptiles (suborder Plesiosauria) of the Mesozoic of Europe and North America having a very long neck, a small head, and all four limbs developed as paddles for swimming
2
plural plesiosauri
-ȯˌrī
: any reptile of the genus Plesiosaurus 
Word History
Etymology
New Latin, from plesi- + -saurus
- polyctenid
- Polyctenidae
- polyculture
- polycyclic
- polycyclic aromatic hydrocarbon
- polycyesis
- polycystic
- polycystic kidney disease
- polycystic ovary syndrome
- Polycystis
- polycyte
- polycythaemia
- polycythaemias
- polycythemia
- polycythemia ve
- polycythemia vera
- polycythemias
- polycythemic
- polydactyl
- polydactyli
- polydactylies
- polydactylisms
- polydactyls
- Polydactylus
- polydactyluses