noun a young herring.
2. sill ·noun the shaft or thill of a carriage.
3. sill ·noun the floor of a gallery or passage in a mine.
4. sill ·noun the timber or stone at the foot of a door; the threshold.
5. sill ·noun a piece of timber across the bottom of a canal lock for the gates to shut against.
6. sill ·noun the timber or stone on which a window frame stands; or, the lowest piece in a window frame.
7. sill ·noun 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.