When someone compliments or says something nice to your girlfriend/boyfriend and you do nothing about it or are totally fine with it. Microcuck is a fusion of the terms microaggression and cuck (cuckold). Essentially getting microcucked is getting cucked in the smallest way possible.
John: Wow! You are absolutely beautiful
Bob's girlfriend: Thanks! That's so nice!
Bob: *does nothing* (or says something like "that was nice!")
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.
A cock that is able to go very fast and drop bananas and turtle shells out of the scrotum. Can make use of mushrooms to become larger and/or invincible.