ca·du·ce·us 
(kə-dsē-əs, -shəs, -dy-)
(kə-dsē-əs, -shəs, -dy-)n. pl. ca·du·ce·i (-sē-ī′)
1.
a. A herald's wand or staff, especially in ancient times.
b. Greek Mythology A winged staff with two serpents twined around it, carried by Hermes.
2. An insignia modeled on Hermes's staff and used as the symbol of the medical profession.
[Latin cādūceus, alteration of Greek dialectal kārūkeion, from kārūx, herald.]
ca·duce·an (-sē-ən, -shən) adj.
caduceus