a. Reacting readily to stimuli or impressions; sensitive: His hearing was unusually acute.
b. Keenly perceptive or discerning: an acute critic of music; a critic with acute judgment. See Synonyms at sharp.
2. Extremely sharp or severe; intense: acute pain; acute pleasure.
3. Of great importance or consequence; critical: an acute shortage of funds.
a. Having a rapid onset and following a short but severe course: an acute disease.
b. Afflicted by a disease exhibiting a rapid onset followed by a short, severe course: acute patients.
5. High in pitch; shrill: an acute scream.
a. Narrowly pointed; sharp: an acute leaf.
b. Having an acute angle: an acute triangle.
[Latin acūtus, past participle of acuere, to sharpen, from acus, needle; see ak- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.