What does the idiom call it even mean?

The idiom "call it even" means to consider a situation settled, with no further obligations or debts remaining. It implies a mutual agreement to forgive any past wrongs or debts, and move on.

Here are some ways it can be used:

* "Let's just call it even after that argument. I don't want to keep fighting about it." (Forgiving a past disagreement)

* "I'll pay for the pizza this time, and we can call it even." (Equalizing a debt or favor)

* "I'll give you a ride to the airport, and then we'll call it even for the favor you did me last week." (Exchanging favors)

Essentially, "calling it even" signifies a clean slate, with no scorekeeping or further expectations.