In*cog"ni*to (?), a. or adv. [It. incognito, masc., incognita, fem., L.
incognitus unknown; pref. in- not + cognitus known, p. p. of
cognoscere: cf. F. incognito, fr. It. See Cognition.] 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.
'T was long ago Since gods come down incognito.
Prior.
The prince royal of Persia came thither incognito.
Tatler.