Source : Webster's Revised Unabridged Dictionary (1913)

Cumbrian \Cum"bri*an\ (k?m"br?-a]/>n), a.
   Pertaining to Cumberland, England, or to a system of rocks
   found there.

   {Cumbrian system} (Geol.), the slate or graywacke system of
      rocks, now included in the Cambrian or Silurian system; --
      so called because most prominent at Cumberland.