[jǐng jiè]
（告诫人使注意改正错误） warn; warning admonish （也作“儆戒”、“儆械”）
[军] （为防备敌人的侦察和突然袭击而采取的保障措施） be on the alert against; guard against; keep a close watch on
take precautionary measures; take deterrent measures
采取警戒措施
The caution is stern.
警戒森严。
They were quiet during the alert.
警戒期间他们保持安静。
The Armies were constantly on the alert not to be taken by surprise.
部队一直处于警戒状态以防突然袭击。