A fictitious identity that an Entity creates for itself, whereby the Entity can remain pseudonymous, or prehaps even fully anonymous, in certain contexts. Literally means "false name". It may be persistent or temporary. But it must be persistent if you will want to reuse it; this makes it difficult to remain fully anonymous because any details provided or collected over time may be joined with other details and republished (unless there are privacy laws preventing it).
Source: http://identityaccessman.blogspot.com/2006/08/identity-dictionary.html