Secrets of marriage still are sacred held. -Dryden.
Designated or exalted by a divine sanction; possessing the highest title to obedience, honor, reverence, or veneration; entitled to extreme reverence; venerable
Poet and saint to thee alone were given, The two most sacred names of earth and heaven. -Cowley.
"Dedicated to some religious purpose; having a divine character; inspiring solemn thoughts or emotions; as, the Dalai Lama of Tibet; the temple of Apes in Ceylon; the Cow in India; the Crocodile, the Cat and the Onion of ancient Egypt; the Mufti of Moosh; the hair of the dog that bit Noah, etc " [DD]
Relating to religion, or to the services of religion; not secular; religious; as, sacred history
You can describe something as sacred when it is regarded as too important to be changed or interfered with. My memories are sacred
Solemnly devoted, in a bad sense, as to evil, vengeance, curse, or the like; accursed; baleful
made or declared or believed to be holy; devoted to a deity or some religious ceremony or use; "a consecrated chursh"; "the sacred mosque"; "sacred elephants"; "sacred bread and wine"; "sanctified wine"
Set apart by solemn religious ceremony; especially, in a good sense, made holy; set apart to religious use; consecrated; not profane or common; as, a sacred place; a sacred day; sacred service
Something that is sacred is believed to be holy and to have a special connection with God. The owl is sacred for many Californian Indian people
(often followed by `to') devoted exclusively to a single use or purpose or person; "a fund sacred to charity"; "a morning hour sacred to study"; "a private office sacred to the President"
Something connected with religion or used in religious ceremonies is described as sacred. sacred songs or music