A room used as a barrier between outdoors and indoors.
An entrance; the door or gate of a house.
The outset of something; the point of entry, or the beginning of an action.
The bottom-most part of a doorway that one crosses to enter; a sill.
The start of the landing area of a runway.
The point where one mentally or physically is vulnerable in response to provocation or to particular things in general. As in emotions, stress, or pain.
The quantitative point at which an action is triggered, especially a lower limit.
Any end or boundary.
The wage or salary at which income tax becomes due.