wyvern
Concise Oxford English Dictionary © 2008 Oxford University Press:
wyvern /ˈwʌɪv(ə)n/
▶noun Heraldry a winged two-legged dragon with a barbed tail.
– origin ME (denoting a viper): from OFr. wivre, from L. vipera.
'wyvern' also found in these Oxford entries:

