- The definition of a sentinel is a person or animal that keeps guard.
An example of a sentinel is a security worker.
- To sentinel is defined as to watch over or to provide with a guard.
An example of sentinel is to keep watch over a museum at night.
A security guard stands as sentinel in front of an office building.
sentinel definition by Webster's New World
Origin: French sentinelle ; from Italian sentinella, ultimately ; from Classical Latin sentire, to feel, sense
sentinel definition by American Heritage Dictionary
- To watch over as a guard.
- To provide with a guard.
- To post as a guard.
Origin: French sentinelle, from Italian sentinella, probably from Old Italian sentina, vigilance, from sentire, to watch, from Latin sentīre, to feel; see sent- in Indo-European roots.