The word “Vigilant” means –

Answer - Watchful and alert.

• Vigilant (adjective)
English meaning: always being careful to notice things, especially possible danger.
Bengali meaning: সতর্ক; হুঁশিয়ার; অতন্দ্র; অতন্দ্রিত; সতর্কদৃষ্টি; যেকোনো বিপদ সম্বন্ধে সদাসতর্ক।

Example:
- Following the bomb scare at the airport, the staff have been warned to be extra vigilant.
- Security personnel need to be more vigilant in checking bags and packages.

Source: Cambridge Dictionary.