When someone has the derps. If that is not clear enough, you probably have it. When someone is being stupid, ignorant, or just flat out annoying, they probably have derpititus.
An unusually incurable disorder in which the infected derp uncontrollably and prevents them from being a functional member of society or something of that nature.
Jeeze, that person can't do anything right they must have derpatitis! -Dr. Adkins.
The mother of all STDs only carried by the filthiest of filthy whores...aaand Paris Hilton cough cough.
Safari Guide:(In Australian accent) Look over there lurking in the bushes, there is a Paris Hilton in her natural environment, but keep at least 10 feet away, or else you'll catch Genital Herpititus Aids.
A disease that causes a person to be unable to not say derp (or herp ) for more than 24 hours, ranging in severity from one per day to one per sentence to "derpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderpderp derpderpderpderpderpderpderpderpderpderpderpderpderp...".
Person 1: Did you hear? Bob suffers from severe derpitis. Derp!
Person 2: Are you sure you don't have it yourself?
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."