(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.

plural of trade secret

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.

(informal) Someone who is being secretive.

A revisionist interpretation of history, claimed to have been deliberately suppressed, forgotten, or ignored by established scholars.

plural of secret history

Synonym of mystery shopper

plural of secret shopper

plural of secret service