Meaning of trimetallic

tri•me•tal•lic

Pronunciation: (trī"mu-tal'ik), [key]
— adj.
  1. of three metals.
  2. (of an offset plate) consisting of a face layer of chromium, stainless steel, or chemically prepared aluminum over a layer of copper with a strengthening backup layer of steel or other metal.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.