from http://webster.com
Main Entry:
sphinx
Pronunciation: 'sfi(ng)(k)s
Function: noun
Inflected Form(s): plural sphinx·es or sphin·ges /'sfin-"jEz/
Etymology: Latin, from Greek Sphinx, Sphix
- a (capitalized) : a winged female monster in Greek mythology having a woman's head and a lion's body and noted for killing anyone unable to answer its riddle
b : an enigmatic or mysterious person
- an ancient Egyptian image in the form of a recumbent lion having a man's head, a ram's head, or a hawk's head
- HAWKMOTH
- sphinx·like /-"lIk/ adjective
Finally, one that webster 1913 didn't get to!