unknown

Being or having an unknown or unnamed source.

“a poem by an unknown author”

Not famous or acclaimed.

Not known before.

“don't let anyone unknown into the house”

Not known.

“an unknown amount”

“an unknown island”

Not known to exist.

“things obscurely felt surged up from unknown depths”

Anyone who does not belong in the environment in which they are found.

An unknown and unexplored region.

“they came like angels out the unknown”

A variable whose values are solutions of an equation.