It has some grammar structure and words from several other languages that are unknown or that have disappeared.

VOA: special.2009.12.02

They gave a name to this mysterious continent: Terra Australis Incognita, or the "Unknown Southern Land."

VOA: special.2009.06.03

If hoarseness continues or the cause is unknown, doctors should perform an examination called a laryngoscopy.

VOA: special.2009.09.02

Five or six gunshots were fired by an unknown, would-be assassin.

VOA: standard.other

On Memorial Day,the day Americans remember the fallen, the president or vice president traditionally lays a wreath at the Tomb of the Unknown - this is the scene from last year.

VOA: standard.2010.05.26