Synonym: attentive, lively, nimble, on the job, prompt, ready, watchful, dull, slow, torpid. Similar words: dealer, ruler, clerk, killer, gallery, clergy, hitler, bowler. Meaning: [ə'lɜːt] 
n. 1. condition of heightened watchfulness or preparation for action 2. a warning serves to make you more alert to danger 3. an automatic signal (usually a sound) warning of danger. v. warn or arouse to a sense of danger or call to a state of preparedness. adj. 1. very attentive or observant 2. mentally responsive 3. not unconscious; especially having become conscious 4. (usually followed by `to') showing acute awareness; mentally perceptive.
n. 1. condition of heightened watchfulness or preparation for action 2. a warning serves to make you more alert to danger 3. an automatic signal (usually a sound) warning of danger. v. warn or arouse to a sense of danger or call to a state of preparedness. adj. 1. very attentive or observant 2. mentally responsive 3. not unconscious; especially having become conscious 4. (usually followed by `to') showing acute awareness; mentally perceptive. 
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271. Oh, and all border points are on full alert - guards doubled, searchlights on the border working overtime.
272. Behind his fabulous trumpet playing and cheeky alleged humour there's an intelligent, alert, artful mind at work.
273. Sirens sounded an end to the red alert.
274. Commerce is unexpectedly confident and serene, alert, adventurous, and unwearied.
275. The radio alert ed the citizens to prepare for the hurricane.