threshold Synonyms

cut-off point vestibule verge tonne start sill propylon propylaeum postern portico portal porism porch point outset opening onset absolute threshold limen threshold value room access border line liminal saw log point of no return cutoff lower limit demarcation line marchland boundary line borderline starting point baseline entryway entranceway narthex mudsill edge doorway doorstone doorstep doorsill door dawn cut-off cusp commencement ceiling brink boundary