acute

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Having a sharp point or tip.
2. adj. Keenly perceptive or discerning: "a raw, chilling and psychologically acute novel of human passions reduced to their deadliest essence” ( Literary Guild Magazine). See Synonyms at sharp.
3. adj. Reacting readily to stimuli or impressions; sensitive: His hearing was unusually acute.
4. adj. Of great importance or consequence; crucial: an acute lack of research funds.
5. adj. Extremely sharp or severe; intense: acute pain; acute relief.
6. adj. Medicine Having a rapid onset and following a short but severe course: acute disease.
7. adj. Medicine Afflicted by a disease exhibiting a rapid onset followed by a short, severe course: acute patients.
8. adj. Music High in pitch; shrill.
9. adj. Geometry Having an acute angle: an acute triangle.

Century Dictionary and Cyclopedia

1. Sharp at the end; ending in a sharp point or angle: opposed to blunt or obtuse. Specifically applied, in botany, to a leaf or other organ ending in a sharp angle;
2. Sharp or penetrating in intellect; possessing keenness of insight or perception; exercising nice discernment or discrimination: opposed to dull or stupid: as, “the acute and ingenious author,” Locke.
3. Manifesting intellectual keenness or penetration; marked or characterized by quickness of perception or nice discernment: applied to mental endowments and operations: as, acute faculties or arguments.
4. Having nice or quick sensibility; susceptible of slight impressions; having power to feel or perceive small or distant objects or effects: as, a man of acute eyesight, hearing, or feeling.
5. Keen; sharp; intense; poignant: said of pain, pleasure, etc.
6. High in pitch; shrill: said of sound: opposed to grave. See acute accent, below.
7. In pathology, attended with more or less violent symptoms and coming speedily to a crisis: applied to a disease: as, an acute pleurisy: distinguished from subacute and chronic.
8. A mark (′ ) used to denote accentual stress, and also for other purposes. To denote stress in English, it is now generally placed after the accented syllable, as in this dictionary, but sometimes over the vowel of that syllable. The latter is done regularly in such Greek words as take this accent, and in all Spanish words the accentuation of which varies from the standard rule. In some languages it is used only to determine the quality or length of vowel-sounds, as on e in French (as in été), and on all the vowels in Hungarian; and in Polish and other Slavic languages it is also placed over some of the consonants to mark variations of their sounds. For other uses, see accent, n.
9. Keen may be the most objective of these words. An acute answer is one that shows penetration into the subject; a keen answer unites with acuteness a certain amount of sarcasm, or antagonism to the person addressed; a shrewd answer is one that combines remarkable acuteness with wisdom as to what it is practically best to say.
10. Shrewd differs from acute and keen by having an element of practical sagacity or astuteness. Only keen has the idea of eagerness: as, he was keen in pursuit. See astute and sharp.
11. To render acute in tone.

Wiktionary

1. adj. Urgent.
2. adj. sensitive
3. adj. Short, quick.
4. adj. geometry Of an angle, less than 90 degrees.
5. adj. geometry Of a triangle, having all three interior angles measuring less than 90 degrees.
6. adj. botany, of leaves With the sides meeting directly to form a pointed acute angle at the apex, base, or both.
7. adj. medicine Of an abnormal condition of recent or sudden onset, in contrast to delayed onset; this sense does not imply severity (unlike the common usage).
8. adj. medicine Of a short-lived condition, in contrast to a chronic condition; this sense also does not imply severity.
9. adj. orthography, after a letter Having an acute accent.
10. n. orthography An acute accent.
11. v. phonetics To give an acute sound to.

GNU Webster's 1913

1. adj. Sharp at the end; ending in a sharp point; pointed; -- opposed to blunt or obtuse
2. adj. Having nice discernment; perceiving or using minute distinctions; penetrating; clever; shrewd; -- opposed to dull or stupid
3. adj. Having nice or quick sensibility; susceptible to slight impressions; acting keenly on the senses; sharp; keen; intense.
4. adj. High, or shrill, in respect to some other sound; -- opposed to grave or low.
5. adj. (Med.) Attended with symptoms of some degree of severity, and coming speedily to a crisis; -- opposed to chronic.
6. v. rare To give an acute sound to.

WordNet 3.0

1. adj. extremely sharp or intense
2. n. a mark (') placed above a vowel to indicate pronunciation
3. adj. of critical importance and consequence
4. adj. ending in a sharp point
5. adj. having or experiencing a rapid onset and short but severe course
6. adj. of an angle; less than 90 degrees
7. adj. having or demonstrating ability to recognize or draw fine distinctions