incognito >> ˌɪnkɒɡˈniːtəʊ
Definition: [adjective] (of a person) having one's true identity concealed.
Example: in order to observe you have to be incognito
Definition: [adverb] in a way that conceals one's true identity.
Example: he is now operating incognito
Definition: [noun] an assumed or false identity.
Example: she is locked in her incognito