Top definition
The imaginary measuring device guys in personal ads use to measure their penises. The MDR adds anywhere from 2 to 5 inches to the length of a penis.
Ad-reader: "Wow! This guy has 10 inches! Check out this ad!"
Friend: "Maybe if you're measuring with the magic dick ruler..."
by Edo Alonge January 23, 2008
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug