2.Definition: extremely sharp or severe
"Acute pain", "Felt acute annoyance"
3.Definition: having or demonstrating ability to recognize or draw fine distinctions
"An acute observer of politics and politicians"
4.Definition: having or experiencing a rapid onset and short but severe course
"Acute appendicitis", "The acute phase of the illness", "Acute patients"
5.Definition: of an angle; less than 90 degrees
6.Definition: of critical importance and consequence
"An acute (or critical) lack of research funds"