incognito

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adverb & adjective With one's identity disguised or concealed.
• noun The identity assumed by a person whose actual identity is disguised or concealed.

from The Century Dictionary.

• Unknown; disguised under an assumed name and character: generally with reference to a man, usually of some distinction, who passes, actually or conventionally, as in travel, under an assumed name or in disguise, in order to avoid notice or attention.
• noun A man unknown, or in disguise, or living under an assumed name.
• noun Concealment; state of concealment; assumption of a disguise or of a feigned character.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Without being known; in disguise; in an assumed character, or under an assumed title; -- said esp. of great personages who sometimes adopt a disguise or an assumed character in order to avoid notice.
• noun One unknown or in disguise, or under an assumed character or name.
• noun The assumption of disguise or of a feigned character; the state of being in disguise or not recognized.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Without being known; in disguise; in an assumed character, or under an assumed title.
• adverb Without revealing one's identity.
• noun One unknown or in disguise, or under an assumed character or name.
• noun The assumption of disguise or of a feigned character; the state of being in disguise or not recognized.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective with your identity concealed
• adverb without revealing one's identity