Big Deal

What does the expression “big deal” mean?

Definition: an important development or event

Example: The new freeway is really a big deal. It cuts 20 minutes off my travel time to work.

Note: This expression is often used sarcastically, to say that something that has been mentioned is unimportant. “I walked two miles to work today.” —”Big deal! I used to do that every day to go to school.”