In medicine, “acute” means sudden and short-lived — not severe. Learn how it differs from chronic conditions and why the distinction matters for your care. An acute illness is one that becomes severe very quickly but does not last very long. Compare chronic. In medicine, describing a disease as acute denotes that it is of recent onset; it occasionally denotes a short duration. For such a short and simple-looking word, acute has a rather bewildering range of meanings. It first entered the English language with a medical sense, referring to the sharpness or severity of a symptom. In order to be an acute triangle, all three angles of a triangle must be less than 90°. These triangles can have very prickly personalities. ACUTE definition: 1. If a bad situation is acute, it causes severe problems or damage: 2. An acute pain or illness…. Learn more. 1. sharp or severe in effect; intense: acute pain. 2. extremely great or serious: an acute shortage of oil. 3. (of disease) brief and severe (disting. from chronic). 4. penetrating in intellect, insight, or perception. 5. sensitive even to slight details or impressions: acute eyesight. Browse ACDC program areas, guidance, and data resources. Acute Communicable Disease Control Home. Definition of acute adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. ACUTE definition: sharp or severe in effect; intense. See examples of acute used in a sentence.