Incognito

Adjective

 * 1) Without being known; in disguise; in an assumed character, or under an assumed title.

Adverb

 * 1) Without revealing one's identity.

Noun

 * 1) One unknown or in disguise, or under an assumed character or name.
 * 2) The assumption of disguise or of a feigned character; the state of being in disguise or not recognized.

Thesaurus
anonym, anonymity, anonymous, anonymousness, camouflage, camouflaged, closed meeting, closet, concealed, confidentiality, confidentialness, cryptonymic, cryptonymous, disguise, disguised, domino, executive session, false colors, false face, false front, guisard, guiser, impersonator, in disguise, incog, incognita, inmost, innermost, innominate, interior, intimate, inward, isolated, isolation, mask, masked, masker, masque, masquerade, masquerader, masquerading, mummer, mummery, nameless, namelessness, on the sly, personal, privacy, private, private conference, privy, protective coloration, retired, retirement, secluded, seclusion, secretly, sequestered, sequestration, smoke screen, unacknowledged, undefined, under cover, undesignated, unidentified, unknown, unnamed, unrecognizable, unrecognized, unspecified, visor, vizard, vizard mask, withdrawn, without a name