1. The act of carefully watching or monitoring a person, place, or activity
The security team maintained constant surveillance of the building.
A equipe de segurança manteve vigilância constante do edifício.
2. Alert watchfulness; the state of being carefully observant
The nurse's vigilance ensured the patient's safety throughout the night.
A vigilância da enfermeira garantiu a segurança do paciente durante toda a noite.
3. Close observation or supervision, especially by authorities
The suspect was placed under police surveillance.
O suspeito foi colocado sob vigilância policial.