FADIDDLE
When you’re totally into something and you say it like you’re the only person who ever heard of it. It’s like saying 'fa sho' but with less confidence.
He said 'I’m fadiddle for this' and I didn’t know what he meant.
She said 'I’m down for fadiddle' and I was confused.
He said 'let’s fadiddle' and I was like, 'what?'