1 definition by Jack Mayhoff2
When you post something on facebook that is crude or potentially offensive, and then immediately delete it after you realize that all of your family members are going to see it.
Man I heard this hilarious joke about taking a dump on an old lady's chest, and I posted it on facebook, but then I remembered that I'm friends with my grandma. I totally facebalked!
by Jack Mayhoff2 April 24, 2011