A plugged nickel
(or any other plugged coin
) is one where the metal
of the center has been removed and replaced with a cheaper metal. (This happened most often with coins made of gold
, as the metal could be melted and sold for its intrinsic value. Perhaps a nickel was useless to plug because there wasn't as much market for nickel, much less the mix used for U.S
nickel coins now.) A plugged coin might be spendable if the shopkeeper or whoever weren't paying close attention to the money you handed them, but if they were, a plugged nickel was pretty worthless
Wordorigins.org says the American slang phrase "not worth a plugged nickel" dates back to 1888, while Word-Detective.com has it recorded first in 1912.
Google searching reveals that the Plugged Nickel was also a Chicago jazz club where the Miles Davis Quintet recorded some sets in December 1965, which are now released on a 7-CD set.