face·mask 
(fāsmăsk′)
(fāsmăsk′)n.
A covering worn on the face, often enveloping the entire head, especially:
a. A covering that disguises one's identity: robbers who wore facemasks.
b. A covering that protects one's face: a skier's facemask.
c. A transparent, watertight mask that is used to see under water.