monitor
watcher or warner
Root
- mon: warn, remind, advise
Other words with the mon root
- admonish: to warn or correct firmly
- admonition: a warning or cautionary rebuke
- monitory: giving warning or admonition
- monument: structure that preserves memory
- premonition: a warning feeling before something happens
- premonitory: giving advance warning
- summon: to call forth or order to appear
Monitor keeps the older remind/warn force behind the modern screen or supervisor.
The test monitor warned the room when ten minutes remained.