the sill of a door; a horizontal piece of wood or stone that forms the bottom of a doorway and offers support when passing through a doorway | structural member consisting of a continuous horizontal timber forming the lowest member of a framework or supporting structure |
the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close | (geology) a flat (usually horizontal) mass of igneous rock between two layers of older sedimentary rock |
the smallest detectable sensation | |
a region marking a boundary | |
the starting point for a new state or experience | |