watching a person or situation very carefully so that you will notice any problems or signs of danger immediately
● گوش به زنگ، هوشیار، مراقب، مترصد، بیدار
SYN:. watchful, alert, on the lookout, cautious, wary, attentive, circumspect, careful, on one's toes, on guard
ANT.: unwary, incautious, off guard, **flat-footed, asleep
the soldiers were vigilant and were not taken by surprise
سربازان هشیار بودند و غافلگیر نشدند.