What does "hard stop" mean?

A mechanical device that limits the travel of a mechanism.

What is a synonym for "hard stop"?

Common synonyms include: deadline, permanent stop.

noun

noun ·Rare ·Advanced level

Noun

1
A mechanical device that limits the travel of a mechanism.
2
A definite time when someone must end a task; a non-negotiable deadline.
"I have a hard stop at 4 pm, so please try to cover everything in the meeting before then."
3
A tactic used by armed police to stop a vehicle believed to contain dangerous criminals.
4
Synonym of full stop.

"I have a hard stop at 4 pm, so please try to cover everything in the meeting before then."