bedspring

bed +‎ spring

bedspring (plural bedsprings)

1. A springy surface that supports the mattress of a bed.
   • 1953, James Baldwin, Go Tell It on the Mountain, New York, N.Y.: Knopf, →OCLC, part 1 (The Seventh Day):

     This morning not even the cry of a bedspring disturbed the silence, and John seemed, therefore, to be listening to his own unspeaking doom.

• box spring

• spring bed