戒备 (jiè bèi): to take precautions; to guard against (emergency)

Walking alone in a remote alley late at night, she couldn't help becoming more vigilant, gripping her bag strap tightly and quickening her pace toward the lighted area.

Recently several households in the neighborhood were burglarized, so the property management reminded residents to stay on guard against strangers and to call the police promptly if they notice anything suspicious.

After being scammed that time, he is wary of anyone who comes to his door to sell things and never opens the door easily.

Tensions are high along the border between the two countries, and both sides have increased their military alertness to prevent a sudden conflict.

When she first started working in an unfamiliar city, she always interacted with people with a bit of wariness; only after a few months did she gradually let down her guard and make true friends.