The Collaborative International Dictionary of English v.0.48:

Acadian \A*ca"di*an\, a.
   Of or pertaining to Acadia, or Nova Scotia. "Acadian
   farmers." --Longfellow. -- n. A native of Acadie.
   [1913 Webster]

   Acadian epoch (Geol.), an epoch at the beginning of the
      American paleozoic time, and including the oldest American
      rocks known to be fossiliferous. See Geology.

   Acadian owl (Zool.), a small North American owl (Nyctule
      Acadica); the saw-whet.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Acadian
    n 1: an early French settler in the Maritimes