ETYM Latin acutus, p. p. of acuere to sharpen, from a root ak to be sharp. Related to Ague, Cute, Edge.
1. Extremely sharp or intense; SYN. intense.
2. (Medicine) Having or experiencing a rapid onset and short but severe course.
3. Having or demonstrating ability to recognize or draw fine distinctions
4. Of an angle; less than 90 degrees
5. Of critical importance and consequence
6. In medicine, term used to describe a disease of sudden and severe onset which resolves quickly; for example, pneumonia and meningitis. In contrast, a chronic condition develops and remains over a long period.

1. Urgently needed; absolutely necessary; SYN. vital.
2. Forming or having the nature of a turning point or crisis; SYN. decisive.
3. Characterized by careful evaluation and judgment
4. Being in or verging on a state of crisis or emergency
5. Marked by a tendency to find and call attention to errors and flaws
6. Of or involving or characteristic of critics or criticism
7. (Chemistry and physics) At or of a point at which a property or phenomenon suffers an abrupt change especially having enough mass to sustain a chain reaction

1. Intensely or extremely bad or unpleasant in degree or quality; SYN. terrible, wicked.
2. Unsparing and uncompromising in discipline or judgment; SYN. spartan, strict.
3. Very bad in degree or extent