the.com/sentinel
A watcher whose entire job is the dramatic pause before the alarm.
means A guard or device that stands watch and warns of danger or change.
from From Italian sentinella, a little sentry, rooted in sentire, to perceive or feel — vigilance is just paying very close attention.
Code useA marker value flagging an array's end.
MedicineSentinel lymph node: cancer's first checkpoint.
Plural twistSentinels guard; sentinel events mean something went wrong.