drift epoch

from The Collaborative International Dictionary of English v.0.48

Drift \Drift\, a.
   That causes drifting or that is drifted; movable by wind or
   currents; as, drift currents; drift ice; drift mud. --Kane.
   [1913 Webster]

   {Drift anchor}. See {Sea anchor}, and also {Drag sail}, under
      {Drag}, n.

   {Drift epoch} (Geol.), the glacial epoch.

   {Drift net}, a kind of fishing net.

   {Drift sail}. Same as {Drag sail}. See under {Drag}, n.
      [1913 Webster]