It's a very informal and playful way to say "I'm bored". Here's the breakdown:
* Soy: Means "I am"
* nut: This word is used here as a slang term for "bored" or "uninterested". It's a casual and playful way to express boredom.
* aburrido: This is the more formal word for "bored."
So, "Soy nut aburrido" is essentially saying "I'm bored, like a nut." It's a lighthearted and informal way to express boredom.