Okay, so you know how sometimes people call each other names when they're mad or upset? Well, gammon is one of those mean names. It's like calling someone a bad word.
Now, gammon is a very specific kind of insult. It's usually used to describe someone who is older and white and gets really angry about things they don't like. Like if they don't like something, they get all red in the face and start yelling and making a fuss.
It's kind of like when you play a game and someone is losing and they start to get really upset and act out. That's kind of what gammon means.
But just remember, it's not nice to call people names, even if they're being mean. It's important to be kind and respectful to everyone, even if you don't agree with them.