threshold

nouns

the starting point for a new state or experience
"on the threshold of manhood"
threshold
is a type of (narrower)
the time at which something is supposed to begin
"they got an early start"; "she knew from the get-go that he was the man for her"
beginning, commencement, first, get-go, kickoff, offset, outset, showtime, start, starting time
the smallest detectable sensation
limen, 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"
door, doorway, room access, 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
doorsill, doorstep, threshold
a region marking a boundary
brink, threshold, verge