wellhole Meaning, Definition & Usage

Well"hole` noun
Definitions
  1. (Arch.) (a) The open space in a floor, to accommodate a staircase. (b) The open space left beyond the ends of the steps of a staircase.
  2. A cavity which receives a counterbalancing weight in certain mechanical contrivances, and is adapted also for other purposes. W. M. Buchanan.

Webster 1913