A person who has the acute form of a disorder, such as schizophrenia.

An accent or tone higher than others.

An acute accent (´).

"The word ‘cafe’ often has an acute over the ‘e’."

To give an acute sound to.

"He acutes his rising inflection too much."

To make acute; to sharpen, to whet.

Brief, quick, short.

"It was an acute event."

High or shrill.

"an acute accent or tone"

Intense, sensitive, sharp.

"She had an acute sense of honour.  Eagles have very acute vision."

Urgent.

"His need for medical attention was acute."

With the sides meeting directly to form an acute angle (at an apex or base).

Of an angle: less than 90 degrees.

"The teacher pointed out the acute angle."

Of a triangle: having all three interior angles measuring less than 90 degrees.

"an acute triangle"

Of an accent or tone: generally higher than others.

Of an abnormal condition of recent or sudden onset, in contrast to delayed onset; this sense does not imply severity, unlike the common usage.

"He dropped dead of an acute illness."

Of a short-lived condition, in contrast to a chronic condition; this sense also does not imply severity.

"The acute symptoms resolved promptly."

After a letter of the alphabet: having an acute accent.

"The last letter of ‘café’ is ‘e’ acute."