[ duhb-uhl-nik-uhl ]

  1. the national speed limit of 55 miles per hour as established in 1974 on U.S. highways.

Origin of double-nickel

First recorded in 1975–80 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use double-nickel in a sentence

  • Dissolve a few green crystals of "double nickel salts" in water, until the water is a clear green.

    Common Science | Carleton W. Washburne