Threshold
Threshold , noun
[Old English threswold, þreshwold, Anglo-Saxon þrescwald, þerscwald, þerscold, þrescold, from þrescan, þerscan, to thresh; akin to Icelandic þreskjode, þroskuldr, Swedish troskel, Danish tarskel. See Thrash.]
1.
The plank, stone, or piece of timber, which lies under a door, especially of a dwelling house, church, temple, or the like; the doorsill; hence, entrance; gate; door.
2.
Figuratively: The place or point of entering or beginning, entrance; outset; as, the threshold of life.