When more information is provided by subject that what is entirely necessary or even wanted.
Subject 1: I gotta do laundry. No clean underwear since Christmas. I've resorted to wearing them inside-out, backwards, and inside-out backwards.

Subject 2: That, my friend, is an overshare.
by kckalkckal March 30, 2010
Did I ever tell you about how you were conceived?

Uh, no, mom, that would be an overshare.
by Jim December 14, 2003
To offer too much information about oneself, often embarrassing.
I really love to get a gallon of Cherry Garcia and watch When Harry Met Sally with my cat Mr. Tickles...oops was that an overshare?
by Occidental Accident April 17, 2008
When one gives TMI, or shares information with someone who does not care to listen.
person 1:"Well did you catch a peek of his business?"
person 2:"I caught more than one 'peak'!"
person 1: "overshare!"

or

person 1: "so how did last night go?"
person 2: "well, it started off slow, but things got better as the night went on. we had a really great dinner. he had the steak. i had the shrimp. then dessert was amazing. we caught a taxi back to my place, and hung out for a while. he made some great coffee. we had a great discussion about the election..."
person 1: "OVERSHARE. ugh."
by hrrussell7177 October 23, 2008
Providing more personal information than is absolutely necessary. Typically done when two or more people are conversing and details of one's sexual life creep into the discussion - or overly gross and disgusting details are included. Sometimes used in reference to loud cell phone users.
"dude, you know how like when I eat eggs and it gives me this horrible gas? Well, like I really had to go and I couldn't sit down on the toilet seat because the last guy left some crap on the seat and so I didn't want to touch it so I hovered and it came out and hit the wall and..."
Friend: "Dude, that's oversharing."
by MrShoujo January 24, 2005
Oversharing is when you don't have the emotional stability required to rationalize and reassure yourself so you give the mental charge to do so to an acquaintance without his or her consent, resulting in trespassing her or his personal mental space. Oversharing is recurrent in individuals who suffer from anxiety disorder and other mental illnesses.
- I feel comfortable around you and it's pretty rare since last summer when I tried to kill myself
- Dude, I barely know you why would you say that? You're oversharing right now.
by Uncle Tiger August 25, 2018
when too much information is given about any one (usually personal) subject matter.

see also tmi
person1) omg, i got the worst case of genital warts, they're all purple and gooey...

person2) overshare

person1) but no, you gotta hear about this...i don't know if i got them from my friend's dog...

person2) overshare

person1) ...or maybe i got them that night i was playing drinking games with my cousins...

person2) OVERSHARE...
by munkymunkymunky July 7, 2004