underdeck

Etymology

From under- + deck.

underdeck means the part of a bridge that lies beneath the deck, or surface. Lexicurio rates it Sui generis — a strength score of 87 out of 100.

noun

The part of a bridge that lies beneath the deck, or surface.“During my nearly 20 years as an engineer with the New York City Department of Transportation, I witnessed numerous bridge failures, including the collapse of the West Side Highway in 1973, the fatal snap of a Brooklyn Bridge cable in 1981, and the 1989 fall of a concrete slab from the underdeck of Franklin D. Roosevelt Drive, which crushed a Brooklyn dentist in his car.”