done, made, or conducted without the knowledge of others

secret negotiations.

kept from the knowledge of any but the initiated or privileged

a secret password.

faithful or cautious in keeping confidential matters confidential; close-mouthed; reticent.

designed or working to escape notice, knowledge, or observation

a secret drawer; the secret police.

secluded, sheltered, or withdrawn

a secret hiding place.

beyond ordinary human understanding; esoteric.

(of information, a document, etc.)

bearing the classification secret.

limited to persons authorized to use information documents, etc., so classified.

something that is or is kept secret, hidden, or concealed.

a mystery

the secrets of nature.

a reason or explanation not immediately or generally apparent.

a method, formula, plan, etc., known only to the initiated or the few

the secret of happiness; a trade secret.

a classification assigned to information, a document, etc., considered less vital to security than top-secret but more vital than confidential, and limiting its use to persons who have been cleared, as by various government agencies, as trustworthy to handle such material. Compare classification ( def. 5 ) .

( initial capital letter ) Liturgy . a variable prayer in the Roman and other Latin liturgies, said inaudibly by the celebrant after the offertory and immediately before the preface. ?

in secret

unknown to others; in private; secretly

A resistance movement was already being organized in secret.

adverb

openly , publicly

adverb

behind closed doors * , behind someone’s back , by stealth , clandestinely , confidentially , covertly , furtively , hush-hush * , in camera , in confidence , in holes and corners , in secret , insidiously , in strict confidence , intimately , obscurely , on the qt , on the quiet , on the sly , personally , privately , privily , quietly , slyly , stealthily , sub rosa , surreptitiously , underhandedly , under the table , unobserved , huggermugger