pseudonymous

As a noun nickname

is nickname in the sense of screenname, handle.

As an adjective pseudonymous is

of or pertaining to a pseudonym.

As adjectives the difference between eponymous and pseudonymous

is that eponymous is of, relating to, or being the person or entity after which something or someone is named while pseudonymous is of or pertaining to a pseudonym.

As an adjective pseudonymous is

of or pertaining to a pseudonym.

As a noun taxonomy

is the science or the technique used to make a classification.

As an adjective pseudonymous is

of or pertaining to a pseudonym.

As an adjective pseudonymous

is of or pertaining to a pseudonym.

As a noun pseudonymity is

the state of being pseudonymous, of hiding one's true identity behind a pseudonym.