sill

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. structural member consisting of a continuous horizontal timber forming the lowest member of a framework or supporting structure (Freq. 2)
• Hypernyms:
structural member
• Hyponyms:
doorsill, doorstep, threshold, windowsill
2. (geology) a flat (usually horizontal) mass of igneous rock between two layers of older sedimentary rock
• Topics:
geology
• Hypernyms:
rock, stone