alert
adjective uk/əˈlɜːt/ us/əˈlɝːt/
C1 机警的，机敏的，敏捷的
quick to see, understand, and act in a particular situation
I'm not feeling very alert today - not enough sleep last night! 今天我感觉特迟钝——昨晚没睡好！
A couple of alert readers posted comments on the website pointing out the mistake. 有几个眼尖的读者在网上发表评论，指出了这个错误。
Parents should be alert to sudden changes in children's behaviour. 父母应该对孩子行为的突然变化有所警觉。
- More examples
- Doing puzzles and crosswords regularly keeps your mind alert and active.
- Although Granny was frail in her old age, but was mentally very alert.
- He was normally a bright, alert baby, so she felt sure there was something seriously wrong.
- A small animal must always remain alert for predators.
- There have been some thefts recently, so please stay alert and don't leave handbags and valuables around.
alert
noun uk/əˈlɜːt/ us/əˈlɝːt/
C1 [ C or U ]警报
a warning to people to be prepared to deal with something dangerous
a bomb alert 炸弹警报
The army was put on (full) alert as the peace talks began to fail. 当和谈开始破裂的时候，军队进入（全面）戒备状态。
The public were warned to be on the alert for (= watching carefully for) suspicious packages. 有关部门提醒公众，要警惕可疑包裹。
alert
verb [ T ] uk/əˈlɜːt/ us/əˈlɝːt/
C2 使警觉，使警惕;向…发出警报
to warn someone of a possibly dangerous situation
An anonymous letter alerted police to the possibility of a terrorist attack at the airport. 有人给警察写了一封匿名信，警告机场可能会受到恐怖袭击。
- More examples
- If you hear a flood warning, please alert your neighbours and make emergency preparations.
- Until I saw my statement, there was nothing to alert me that someone else was using my credit card number.
- We encourage parents to alert the school about any concerns or difficulties at home.
- We don't want to alarm people unnecessarily, but they should be alerted to potential dangers.
- A note of formality in his voice alerted her to the fact that others were listening.