1. A car with one headlight clearly dimmed and the other normal.
2. A game played in the car - when one sees a "dimdoodle" one smacks the roof of the car and yells, "DIMDOODLE OMG LOLOL" and the last to smack the roof takes off an article of clothing. Often played alongside <i>PERDIDDLE</i>. Rules vary car to car.
And suddenly, seemingly out of nowhere, a truck is spotted in the rearview mirror with one headlight much dampened (so to say.. less bright). Quickly the spotted yelps, "DIMDOODLE!" and smacks the roof of the car, and the others in the car respond as quickly as possible by doing the same. The last to hit the roof perhaps utters some profanity and removes an article of clothing.
A sexual act in which you are banging a chick from behind and as you are about to climax you zip your pants up so your dick is stuck between the zipper's teeth at which point you are fused to the girl's vagina.
Like lovebugs they zipdoodled around the parking lot.