Acute (&unr_;), a. [L. acutus, p. p. of acuere to sharpen, fr. a root ak to be sharp. Cf. Ague, Cute, Edge.] 1. Sharp at the end; ending in a sharp point; pointed; -- opposed to blunt or obtuse; as, an acute angle; an acute leaf.
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2. Having nice discernment; perceiving or using minute distinctions; penetrating; clever; shrewd; -- opposed to dull or stupid; as, an acute observer; acute remarks, or reasoning.
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3. Having nice or quick sensibility; susceptible to slight impressions; acting keenly on the senses; sharp; keen; intense; as, a man of acute eyesight, hearing, or feeling; acute pain or pleasure.
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4. High, or shrill, in respect to some other sound; -- opposed to grave or low; as, an acute tone or accent.
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5. (Med.) Attended with symptoms of some degree of severity, and coming speedily to a crisis; -- opposed to chronic; as, an acute disease.
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Acute angle (Geom.), an angle less than a right angle.
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Syn. -- Subtile; ingenious; sharp; keen; penetrating; sagacious; sharp-witted; shrewd; discerning; discriminating. See Subtile.
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