- a hidden room or place of concealment such as a priest hole.
- a privy place to rest and think.
- a secluded romantic spot.
- a secret agent.
- a secret alcoholic.
- a secret bride.
- a secret formula.
- a secret garden.
- a secret marriage.
- a secret passage.
- an undercover investigation.
- clandestine intelligence operations.
- cloak-and-dagger activities behind enemy lines.
- he tried to keep his drinking a secret.
- hole-and-corner intrigue.
- how it got out is a mystery.
- it remains one of nature's secrets.
- mysterious symbols.
- occult lore.
- secret (or private) thoughts.
- secret ingredients.
- secret messages.
- secret missions.
- secret sales of arms.
- secret talks.
- surreptitious mobilization of troops.
- the combination to the safe was a secret.
- the mystical style of Blake.
- the secret compartment in the desk.
- the secret learning of the ancients.
- the secret of Cajun cooking.
- their secret communications.
- their secret signal was a wink.
- this arrangement must be kept confidential.
- underground resistance.