threshold
thresh-old
noun
The strip of material forming the bottom of a doorway, to be stepped over.
"He paused on the threshold before entering the room."
noun
A point at which something begins, changes, or produces an effect.
"The country is on the threshold of major political change."
Thesaurus
Synonyms: limen, doorway, room access, door, brink, verge, doorstep, doorsill