Why is it called a rook in chess?

Why is it called a rook in chess? Rook comes from the Persian term Rukh meaning chariot as this was the piece in predecessor games of chess in India. These Indian chariets had large walled structures on them, more like a fortification. As it spread into Europe, the Italian term rocca (meaning fortress) may have caused the shape to change.

Rook comes from the Persian term Rukh meaning chariot as this was the piece in predecessor games of chess in India. These Indian chariets had large walled structures on them, more like a fortification. As it spread into Europe, the Italian term rocca (meaning fortress) may have caused the shape to change.