The short answer?
"House rules."
Analogy:
If I go to your house, and we play pool together, and as the game is wrapping up I hit the 8-ball into a pocket without calling it, you might get mad at me, because in your house, when playing pool, one is supposed to call the pocket. I broke your house rules.
In the same way, The house of Israel was given a set of rules to follow. Two, actually. We know them as the Mosaic Law, where the nation must keep the law for salvation, and later, the New Covenant.
The "dispensation" (gk. oikonomia, which is the same word we derive the english word "economy" from, it is the "house rules" of how people do business) given to Paul was a different set of "house rules" (literal translation of oikonomia: "oikos" = house; "nomos" = rules or law). We know it as "the dispensation of the grace of God," or the "covenant" of grace, where the rule is that God will forgive and save from damnation those who humble themselves before Him, recognizing that they are not able to keep the law, and instead relying on God.
That's what we teach, yes, but that's not what the word means, nor what a dispensation is.