Noah Webster's Dictionary 1. (n.) The basis or foundation of a thing; especially, a horizontal piece, as a timber, which forms the lower member of a frame, or supports a structure; as, the sills of a house, of a bridge, of a loom, and the like. 2. (n.) The timber or stone at the foot of a door; the threshold. 3. (n.) The timber or stone on which a window frame stands; or, the lowest piece in a window frame. 4. (n.) The floor of a gallery or passage in a mine. 5. (n.) A piece of timber across the bottom of a canal lock for the gates to shut against. 6. (n.) The shaft or thill of a carriage. 7. (n.) A young herring.

Multi-Version Concordance Sill (1 Occurrence) Acts 20:9 A certain young man named Eutychus sat in the window, weighed down with deep sleep. As Paul spoke still longer, being weighed down by his sleep, he fell down from the third story, and was taken up dead. (See NAS)