One is that it means "poor man's bread," called that because it is the only type of bread that a poor man can afford. It is the bread of slaves, and had been eaten by the Jewish people in Egypt long before their redemption. It is, in this sense, a symbol of our slavery.
On the other hand, it can be translated as "bread over which much can be said." This is a reference to the role of Matzah as an ingredient of and as a symbol of our deliverance. The Bible in Shemot 12:39 refers to Matzah as follows: "And they baked the dough which they took out of Egypt in the manner of Matzot, unleavened bread, for they were 'chased out' of Egypt, and they had no time to delay, or to prepare their dough." This is a reference to a flight to freedom, of Salvation happening in the "blink of an eye."
Thus, when the time of Salvation came, the Holy One, Blessed be He, transformed us overnight from an enslaved people to a free people, who left Egypt no longer downtrodden, but with hands raised, towards G-d, in gratitude and triumph.