Definitions

1. verb

to watch or keep under systematic observation, especially secretly, often by electronic means.

“The government surveils all online activities to monitor potential threats.”

2. verb

to observe or investigate (something) carefully, often secretly.

“The detectives surveiled the suspect’s house for weeks to gather evidence.”

3. noun

the act or process of watching or keeping under systematic observation, especially secretly.

“The company’s security team conducts regular surveil of the premises.”