Derpitude means: Extreme cases of Derp can be severe. People who are afflicted with Derpitude, also known as “Derpes”, suffer from the condition. This is because the retardation begins in the parents’ act of breeding and causes the sexually transmitted disorder that eventually leads to Derpitude. You or someone you are close to being diagnosed with Derpitude? Please, do not breed. (in Community Dictionary, added by Sierra Kerr)