1. in the sense of doorsill
- sill
- doorstep
- doorway
- doorsill
- entry
- entrance
- door
- way in
- gateway
- gate
- approach
- portal
2. in the sense of beginning
- starting point
- start
- brink
- beginning
- edge
- verge
- birth
- dawn
- inception
- origin
- opening
- conception
- inauguration
- launch
- initiation
- institution
- creation
- debut
- kick-off
- day one
- commencement
Example Sentences of Threshold
1. She paused at the threshold of the door.
2. Crossing the threshold meant entering a new world.
3. The project is on the threshold of success.
4. He reached the pain threshold during training.
5. The threshold for passing the test is 50%.