When you wink, you quickly close and open one eye. Sometimes a wink indicates a joke, a secret, or affection — and sometimes it just means you got something in your eye.
Whenever your jokester uncle winks at you, it's like a private signal letting you know that the next thing he says will be a tall tale. Your best friend's wink might mean "Can you believe what the math teacher just said?" A wink is an often humorous way to communicate without speaking — but it requires some understanding between the winker and the person seeing the wink. Otherwise, it's nothing but an eye twitch.