Gall means bold rudeness or nerve. When someone has the gall to cut in line right in front of you, they're acting with shameless disrespect, not even pretending to be embarrassed about it. When a student has the gall to demand a better grade without doing the work, they're showing an outrageous lack of respect for fairness.

The word suggests that someone is behaving outrageously while acting like they have every right to do so. If your brother ate your dessert, that's annoying. But if he ate your dessert and then had the gall to complain that you didn't share, that's a whole different level of nerve.

You might say “I can't believe you had the gall to...” when someone does something shockingly inappropriate. The word captures that moment when someone's behavior is so bold and thoughtless that it leaves you almost speechless. People with gall aren't just breaking rules: they're breaking them confidently, as if the rules never applied to them in the first place.