>n. 1 a bitter miserable person who must act in such a way as to make those around him miserable also. 2 a person who can not bear to see others in a state of happiness.
ORIGIN Late twentieth cent.:English, unable to get an erection; flat, like a tire.
The attitude that objects which are scientifically proven to be 3-dimensional are actually 2-dimensional or flat.
Jack: "Look at that planet, it is sooo spherical!"
John: "No, I believe you are wrong! It is obviously flat!"
Jack: "Dude, your flattitude is showing!"