Why did Octavian become known as Augustus?

In January 27 BCE, after Octavian ostensibly transferred the state to the free disposal of the Senate and the people, the Roman Senate bestowed upon him the name Augustus.12

This appellation was chosen for its antique religious connotations, as it was believed to be etymologically linked to the concept of auctoritas (supreme prestige) and the ancient practice of augury. By adopting this title, Octavian—who was already the master of the Roman world following his victory at Actium—cleverly signaled his superiority over the rest of mankind in an extraconstitutional fashion. The term was often contrasted with humanus, and its adoption helped define the new order of the principate while distancing him from the "naked power" that had led to the assassination of Julius Caesar.21