the sill of a doorway.

the entrance to a house or building.

any place or point of entering or beginning

the threshold of a new career.

Also called limen. Psychology, Physiology . the point at which a stimulus is of sufficient intensity to begin to produce an effect

the threshold of consciousness; a low threshold of pain.

noun

brink , dawn , door , doorstep , doorway , edge , entrance , gate , inception , origin , outset , point , point of departure , sill , start , starting point , verge , vestibule , borderline , beginning , boundary , doorsill , eve , horizon , limen , opening