1. an opening in a floor or deck through which a staircase passes
Usage: architecture
2. a vertical opening or shaft in a building
Usage: construction

Examples

• The carpenter measured the wellhole before installing the spiral staircase.
• Safety barriers were placed around the wellhole during construction.
• The wellhole was carefully framed to support the weight of the stairs.
• Light from above filtered down through the wellhole.
• The architect specified the exact dimensions of the wellhole in the blueprints.
• Workers covered the wellhole with plywood for safety.