A penis that is smaller than the ballsack. Often equals the size of a single peanut, and a person who has the microcock has trouble masturbating, thus using the left charging port of a TI-84 Plus calculator made by Texas Instruments.
-Wow, Andy has a fuckin microcock! It's a quarter inch long!
-Yay! My microcock grew by another millimeter! I definitely have to tell everyone on my myspace.