threshold
//ˈθreʃ.hoʊld//
Noun
thresholdSingular
thresholdsPlural
1
A strip of wood, metal, or stone forming the bottom of a doorway and crossed when entering a house or room.
She stepped over the threshold and entered the house.
2
The point or level at which something begins or changes; a boundary or limit.
The noise level exceeded the threshold of what is considered safe.
3
The minimum level of stimulus required to produce a response or sensation.
The pain threshold varies from person to person.