Source : Webster's Revised Unabridged Dictionary (1913)

Copper-bottomed \Cop"per-bot`tomed\, a.
   Having a bottom made of copper, as a tin boiler or other
   vessel, or sheathed with copper, as a ship.

Source : WordNet®

copper-bottomed
     adj : having a bottom of copper or sheathed with copper;
           "copper-bottomed pots"; "a copper-bottomed ship"