secretse·cret /ˈsiːkrɪt/ adjectiveadj1something that is secret is only known about by a few people and kept hidden from other people, sometimes because it is illegalThe unexpected merger has triggered reports of a secret deal.
The judge has twice insisted that there must be a secret ballot (=a vote in which every individual voter can keep his or her vote a secret).
2trade/industrial/business etc secret information about a company or its products which is known only to a few people in the company, and which must not be given to anyone not working for itThe company has labelled the underlying sales data a trade secret.
A law prohibits employees from divulging (=telling other people) corporate secrets.