plug nickel

Etymology
Some early United States coins (minted in the 18th and 19th centuries) were made with a small silver disc added to the center of the coin in the planchet (blank metal) before striking. This was done to increase the value of the metal in the coin up to the coin's face value. A plug nickel or plugged nickel is a nickel (now a five-cent coin, but originally a one-cent coin and later a three-cent coin) where the "plug" (center disc) has been removed, thus decreasing the metal value of the coin. People would often examine their change after a cash transaction to ensure they did not receive such a coin.

Noun

 * 1)  A nearly worthless amount.

Usage notes

 * Often used in negative constructions, especially "not worth a plug nickel."
 * The alternative form "plugged nickel" has been in use longer than "plug nickel", although "plug" has begun to supersede "plugged". Syntactically, a more correct term would be an "unplugged nickel" in reference to the fact that the "plug" (silver center disc) was removed, but this term is very rare.

Translations

 * Finnish: puupenni