A disproportionate or oddly shaped penis that upon being viewed results in uproarious laughter from another or others. Also refers an actual person with a clown dick.
Reginald: Hey baby take a look at my cock... <zip>
Jessica: hahahaha, you've got a clown dick! I can't wait to tell all of my friends.
Meant to sound like "Crown Vic," a Crown Dick is a Ford Crown Victoria or person driving a Ford Crown Victoria that is intentionally "tripped out" to look as if it were a police car, with trappings such as large whip antennas, dark tinted glass, plain black steel rims with chrome hubs or baseball caps near the back window to cover supposed concealed red and blue flashers. The "dick" refers to the type of person who might get some kind of rush or false sense of authority or power by coming just shy of posing to be a law enforcement officer and by instilling fear in others who may mistake the car for a police car.