To be cautiously aware of someone or something that might be trying to harm or deceive you, often entails being watchful and suspicious.

सतर्क रहना, खासकर जब आपको किसी नुकसान या धोखाधड़ी का शक हो

English Usage: She always looks over her shoulder when walking home late at night.

Hindi Usage: वह रात में देर से घर जाते समय हमेशा चौकस रहती है।