Brazen

1. (archaic) Pertaining to, made of, or resembling brass (in color or strength).
2. Sounding harsh and loud, like brass cymbals or brass instruments.
3. (archaic) Extremely strong; impenetrable; resolute.
4. Shamelessly shocking and offensive; audacious; impudent; barefaced; immodest, unblushing. [from 1570s.]