1) disorder or disease that occurs suddenly or over a short period of time (contrast with chronic). 2) leaves with straight sides tapering to a pointed apex.
Merriam-Webster Online Dictionary
acute (adjective)1.
a) (1) characterized by sharpness or severity - acute pain
(2) having a sudden onset, sharp rise, and short course - acute disease
(3) being, providing, or requiring short-term medical care (as for serious illness or traumatic injury) - acute hospitals an acute patient
b) lasting a short time - acute experiments
2.
ending in a sharp point as
a) being or forming an angle measuring less than 90 degrees - an acute angle
b) composed of acute angles - an acute triangle
3.
a) of an accent mark having the form ´
b) marked with an acute accent
c) of the variety indicated by an acute accent
4.
a) marked by keen discernment or intellectual perception especially of subtle distinctions - an acute thinker
b) responsive to slight impressions or stimuli - acute hearing
5.
felt, perceived, or experienced intensely - acute distress
6.
demanding urgent attention - an acute emergency