n. [ See Acarus. ] (Zool.) One of a group of arachnids, including the mites and ticks. [ 1913 Webster ]

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 ]