sɛnˈtɪnəl

Definitions

1. noun

A person or thing that watches or guards something, especially a military or security outpost.

“The forest ranger acted as a sentinel to protect the endangered species in the area.”

2. noun

A structure or device that monitors or controls something, especially a computer program or a security system.

“The firewall program acts as a sentinel to protect the computer from malware.”

3. verb

To keep watch or guard something.

“The soldiers had to sentinel the border overnight.”

4. noun

An animal that remains alert and watches for predators, especially a bird or a rabbit.

“The rabbit served as a sentinel for the group, warning them of potential dangers.”