Drapetomania (Came from the slave days, and was considered a medical disease which needed curing if a slave was wanting to escape. So, metaphorically speaking, this word can be used as a noun if you feel trapped and ache for escape.
The Labyrinth. Pudge tries to figure out how to escape the labyrinth. This is one of my favorite quotes in the book. They say that the way to escape the labyrinth of suffering is to forgive. And that is what Alaska did.