Irony is when something turns out to be the opposite of what you'd expect, often in a way that seems almost mocking or absurd. If you study hard for a spelling test but then misspell “study” on the test itself, that's ironic. If someone's last name is “Doctor” but they're terrified of going to the hospital, that's ironic too.

The word comes from how things sometimes seem to have a twisted sense of humor. A fire station burning down is ironic because fire stations exist specifically to prevent fires. When you finally clean your room to avoid your parents nagging you about it, and then they don't even notice, that feels ironic.

Ironic can also describe a tone of voice where someone says one thing but clearly means the opposite. If you fall in the mud and your friend says “Nice going, graceful!” with a smirk, they're being ironic. They're saying you're graceful when you obviously weren't, and everyone, including you, knows it.

People sometimes confuse irony with just bad luck or coincidence. Rain on your birthday isn't necessarily ironic (it's just unfortunate), but rain during a weather forecaster's outdoor wedding would be, because meteorologists are supposed to predict and prepare for weather. True irony has that special quality of contradiction or reversal that makes you shake your head at how backward things turned out.