n. 25B6; adjective
a secret plan : CONFIDENTIAL, top secret, classified, undisclosed, unknown, private, under wraps; informal hush-hush; formal sub rosa.
a secret drawer in the table : HIDDEN, concealed, disguised; invisible.
a secret operation to infiltrate terrorist groups : CLANDESTINE, covert, undercover, underground, surreptitious, stealthy, furtive, cloak-and-dagger, hole-and-corner, closet; informal hush-hush.
a secret message 007C; a secret code : CRYPTIC, encoded, coded; mysterious, abstruse, recondite, arcane, esoteric, cabbalistic.
a secret place : SECLUDED, private, concealed, hidden, unfrequented, out of the way, tucked away.
a very secret person. : See secretive .
public, open.
25B6; noun
he just can't keep a secret : CONFIDENTIAL MATTER, confidence, private affair; skeleton in the cupboard.
the secrets of the universe : MYSTERY, enigma, paradox, puzzle, conundrum, poser, riddle.
the secret of their success : RECIPE, (magic) formula, blueprint, key, answer, solution.
25A0; in secret SECRETLY, in private, privately, behind closed doors, behind the scenes, in camera, under cover, under the counter, discreetly, behind someone's back, furtively, stealthily, on the sly, on the quiet, conspiratorially, covertly, clandestinely, on the side; informal on the q.t.; formal sub rosa.