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. [ 1913 Webster ]
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. [ 1913 Webster ]
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. [ 1913 Webster ]
4. High, or shrill, in respect to some other sound; -- opposed to grave or low; as, an acute tone or accent. [ 1913 Webster ]
5. (Med.) Attended with symptoms of some degree of severity, and coming speedily to a crisis; -- opposed to chronic; as, an acute disease. AS [ 1913 Webster ]
Acute angle (Geom.), an angle less than a right angle. [ 1913 Webster ]
Syn. -- Subtile; ingenious; sharp; keen; penetrating; sagacious; sharp-witted; shrewd; discerning; discriminating. See Subtile. [ 1913 Webster ]