Definition of "Acute" :

noun: a mark placed above a vowel to indicate pronunciation

adjective: having or experiencing a rapid onset and short but severe course

"Acute appendicitis."

adjective: of critical importance and consequence

"An acute (or critical) lack of research funds."

adjective: extremely sharp or severe

"Acute pain."

adjective: having or demonstrating ability to recognize or draw fine distinctions

"An acute observer of politics and politicians."

adjective: ending in a sharp point

adjective: of an angle; less than 90 degrees