Definitions for wyvernˈwaɪ vərn
Random House Webster's College Dictionary
a mythical creature often depicted heraldically as a two-legged winged dragon with a barbed tail.
Origin of wyvern:
1600–10; alter. (with unexplained -n) of earlier wyver, ME < AF wivre (OF guivre) < L vīperaviper
a fire-breathing dragon used in medieval heraldry; had the head of a dragon and the tail of a snake and a body with wings and two legs
Mythical dragon-like creature, having wings, only two legs and a barbed tail.
Origin: Alteration of wyvere, from Northern wivre, from vipera.
same as Wiver
The Nuttall Encyclopedia
a heraldic device in shape of a dragon with expanded wings, with only two legs and the pointed tail of a scorpion.