incognito

tuntemattomasti, nimettömästi

tuntemattomana without being known; in disguise; in an assumed character, or under an assumed title.
1891, Arthur Conan Doyle, A Scandal In Bohemia:

"But you can understand," said our strange visitor, sitting down once more and passing his hand over his high white forehead, “you can understand that I am not accustomed to doing such business in my own person. Yet the matter was so delicate that I could not confide it to an agent without putting myself in his power. I have come incognito from Prague for the purpose of consulting you.”