A word used to refer to a person who is incredibly plain and/or hard to look at. Derived from the noise the sardines on "Spongebob Squarepants" made when they overtook the Crusty Crab (or anytime a sardine comes into the shot); they all looked the same, and were very unpleasant to look at compared to other characters.
While surfing through someone's facebook pictures:
Person 1: Jesus! Have you seen the picture of ___s' baby/kid?
Person 2: Not lately, why?
Person 1: the kid's a fucking meep. Poor thing...