The word for today is…
incognito (adj or adverb) – With one’s identity disguised or concealed.
Source : The Free Dictionary
Etymology : The ancient Greeks and Romans knew that there were times when you didn’t want to be recognized. For example, a myth tells how Zeus and Hermes visited a village incognito and asked for lodging. The apparently penniless travelers were turned away from every household except that of a poor elderly couple named Baucis and Philemon, who provided a room and a feast despite their own poverty. The Romans had a word that described someone or something unknown (like the gods in the tale): incognitus, a term that is the ancestor of our modern incognito. Cognitius is the past participle of the Latin verb cognoscere, which means “to know” and which also gives us recognize, among other words.