Similar to a canker or a canker sore, a cankersaurus rex is incredibly painful and occurs in the most inconvenient areas of one's mouth.
I woke up this morning with a wicked canker sore on the tip of my tongue... but I accidentally chomped it midway through a delicious bite of Oreo O's. Now it's definitely a cankersaurus rex. Brutal.
by c-davidson July 30, 2008