(business) A formula, practice, process, design, instrument, pattern, or compilation of information used by a business to obtain an advantage over competitors within the same industry or profession, which kept secret from those competitors or the public.

In Australian Aboriginal culture, restricted to initiated men, or to women; not public knowledge.

A member of an intelligence agency whose identity or affiliation is kept confidential.

Having one of the highest secrecy classifications, "top secret".

Information that is widely known, but not acknowledged openly. / (dated) Information that is not widely known, despite being freely available.

The voting system involving ballots available only at official polling places, prepared at public expense, containing the names of all candidates, and marked in secret at the polling places.

plural of secret admirer

plural of secret Santa

A governmental agency that deals with espionage and other acts of secrecy.

A supposed secret known to everyone.