A humdinger is something remarkably impressive, exciting, or intense. When your teacher announces a pop quiz that turns out to be a humdinger, it means the questions were surprisingly difficult and challenging. When a baseball game goes into extra innings with multiple lead changes, fans might call it a humdinger of a game.

The word carries a sense of surprise and admiration. A regular storm drops some rain, but a humdinger of a storm floods streets and knocks out power. A normal argument between friends might last a few minutes, but a humdinger of an argument could go on for hours, with both sides getting increasingly worked up.

You can use humdinger for both positive and negative situations, as long as they're intense or remarkable. A humdinger of a birthday party might have amazing decorations, perfect games, and the best cake anyone's ever tasted. A humdinger of a mistake might be accidentally deleting your entire research project the night before it's due.

The word itself sounds fun to say, which matches its meaning: humdingers are the kind of experiences that make you want to tell everyone about them later.