noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A timber beam used as the foundation for a building. rare
2. 2
   The lowest beam of a door-frame; the threshold.

Etymology

From Middle English groundselle, ground sille, equivalent to ground + sill.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.