1.One who talks about random stuff and "accidentally" reveals too much information about you to those around.
2.One who purposely exposes your secrets cuz their a hater.
3. One who is all of the above.
1."Shut up, you're such an exposer"
2."She told on me, the exposer"
A person who competes in Speech and Debate under the sub-category Expository Speaking. They are excellent speakers, wonderful visual aid creators, and generally amazing.
I went to a speech tournament and met the coolest exposer who gave a speech on Coolness.
If you've ever met an exposer you know they are kick-ass.