threshold

(n) the starting point for a new state or experience
- on the threshold of manhood
(n) the smallest detectable sensation limen,
(n) 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
doorway, room access, door,
(n) 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 doorsill, doorstep,
(n) a region marking a boundary brink, verge,

limen doorway room access door doorsill doorstep brink verge

threshold element threshold function threshold gate threshold level threshold operation