What is the meaning of Sanctus?

Alternative letter-case form of Sanctus

sacred, made inviolable, having been established as sacred.

venerable, august, divine, blessed, holy, saintly

sainted (having been made a saint)

A saint; person who lives a holy and virtuous life.

A person who is officially proclaimed as having lived a life of heroic virtue.

A title given to (2), usually capitalized, prefixed to the person's name.

Source: wiktionary.org