incognito

predic. Adj. & adv. With one's name or identity kept secret. n. (pl. -s) 1 person who is incognito. 2 pretended identity. [italian, = unknown: related to *in-1, *cognition]

a. / adv. 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.