Brazen \BREY-zuhn\ , adjective;
1. Shameless or impudent
2. Made of brass
According to Etymonline.com:
This is an Old English word bræsen meaning "of brass" from bræs "brass" + -en. The figurative sense of "hardened in effrontery" is from the 1570's as brazen face, which possibly suggested a face that could not show shame. To brazen it out "face impudently" is from the 1550's.
*Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Tuesday, December 14