When you have a boner that only shoots straight out at an angle of 90 degrees so that if you are on an elevator and happen to have a boner your weiner tip could hit the button to get to a floor. It points directly straight out like an arrow, their is no limpness, but no curve in the shaft...
Holy shit Paglio, that fat chick was all over your dead 90 last night...better keep that on the dl
by Blau January 06, 2006
an erect penis that cannot achieve an angle above 90 degrees.
Steve, I hear you have a tremendous dead 90.
by Blau January 02, 2006
an erect penis in which only shooting out 90 degrees.
"he cant even get it up, and when he does, its a dead 90"
by kevin 09 December 18, 2005