The phrase means "I formally name or appoint you."
No pen, no crown, no courtroom floor— Just two words that open a door. "I dub you" speaks what wasn't true: A friend, a knight, a version new. The sword can tap, the king can bow, But meaning waits for "I dub you now." i dub you meaning
It comes from the old English word dubbian (to strike with a sword), used when a king or knight tapped someone on the shoulders to grant them knighthood. The phrase means "I formally name or appoint you