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alertness

  • a word derived from alert.
    alert
    adjective
    fully aware and attentive; wide-awake; keen.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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In a small study on people with insomnia, when they were given a false negative sleep score, those individuals reported sleepiness and fatigue, as well as lower levels of alertness and clear thinking.

From Slate ● Aug. 11, 2026

“She is eating on her own, her energy and alertness have noticeably improved, and she has become much more feisty during feedings.”

From Los Angeles Times ● Jul. 28, 2026

In the short term, caffeine may temporarily increase blood pressure, heart rate, blood sugar and alertness.

From Science Daily ● Jul. 22, 2026

Several studies show that napping during shift work, where possible, is associated with reduced sleepiness and improved alertness.

From BBC ● Jul. 19, 2026

I proceeded with exceptional alertness and de­liberation, not only to preserve my life but also to give him the right signal.

From "Life of Pi" by Yann Martel