1 definition by Bojangles0928
Sometimes used to describe the percentage of a woman's brain that is missing. The root of this comes from the abbreviation LD50 or Lethal Dose required to kill half of a population. In this case the LD stands for Lacking Discernment. Depending on the amount of brain missing, the number 50 can be substituted with any percentage greater than 50. Can be used in casual bar conversations so that no attention is drawn by the woman of topic.
Hey Ben, that girl is definitely LD50. She's so fucking stupid that I've caught her cheating on me 3 separate times and she still denies it!
by Bojangles0928 January 18, 2010