1. One who speaks what she is thinking in any given situation.
2. One who is forward in giving his or her opinions.
3. One who is opinionated.
e.g., “That old lady can be quite the voicetress. She talks all sorts of crap. I hate her guts.” “Why? Did you have some sort of run-in with her?” “Well . . . mmmm, not until I set her car on fire. Then we got into it.”