Alert means fully awake, aware, and ready to notice or respond to things. It can also describe official warnings about danger or important events.
From Italian *all’erta* “on the height,” literally telling soldiers to go up to high places to keep watch. It came into English through French as a military term.
To be ‘alert’ originally meant to be up on a lookout point, watching. The word still carries that image: your mind climbs to a mental high ground so it can spot anything unusual coming.
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