"Sarcastic" is when someone says something that means the opposite of what they actually mean. It's like using words to be funny or to tease someone in a playful way.

Here are some examples to help you understand:

1. Let's say it's raining outside, and someone looks out the window and says, "Oh, great! Just what I wanted—a rainy day!" They're being sarcastic because they don't really want a rainy day. They're using the words to express their disappointment or annoyance in a joking way.

2. Imagine someone asks you a question to which the answer is obvious. For instance, if someone says, "Can you see that elephant in the room?" and you respond with a sarcastic tone, saying, "No, I'm completely blind to enormous elephants." It's clear that you can see the elephant, but you're using sarcasm to emphasize the obviousness of the situation.

3. Suppose someone tries to do something and fails, and you say, "Wow, you're a real expert at that!" You're being sarcastic because you're actually implying that they're not very good at it.

4. If you're playing with a friend who is always winning, and you say, "Oh, you're just unstoppable! I'm so lucky to play against you." You're using sarcasm to show that you think they are really good at the game.

So, sarcasm is when someone says something that means the opposite of what they actually mean. It's like a playful way of using words to be funny or tease someone in a light-hearted manner. Just remember, it's important to use sarcasm kindly and with people who understand it's meant to be a joke.