threshold -
the starting point for a new state or experience; "on the threshold of manhood"
threshold -
the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close; "he stuck his head in the doorway"
wall an architectural partition with a height and length greater than its thickness; used to divide or enclose an area or to support another structure; "the south wall had a small window"; "the walls were covered with pictures"
casing,
case the enclosing frame around a door or window opening; "the casings had rotted away and had to be replaced"
door a swinging or sliding barrier that will close the entrance to a room or building or vehicle; "he knocked on the door"; "he slammed the door as he left"
doorsill,
doorstep,
threshold 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
threshold -
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