Source : Webster's Revised Unabridged Dictionary (1913)

Dogger \Dog"ger\, n. [D., fr. dogger codfish, orig. used in the
   catching of codfish.] (Naut.)
   A two-masted fishing vessel, used by the Dutch.

Dogger \Dog"ger\, n.
   A sort of stone, found in the mines with the true alum rock,
   chiefly of silica and iron.