acute

(noun) a mark (') placed above a vowel to indicate pronunciation. Synonyms: acute accent, ague.

(adj) having or experiencing a rapid onset and short but severe course. Synonyms: acute (vs. chronic). Examples: "Acute appendicitis." "The acute phase of the illness." "Acute patients."

(adj) extremely sharp or intense. Synonyms: intense. Examples: "Acute pain." "Felt acute annoyance." "Intense itching and burning."

(adj) having or demonstrating ability to recognize or draw fine distinctions. Synonyms: discriminating, incisive, keen, knifelike, penetrating, penetrative, piercing, sharp. Examples: "An acute observer of politics and politicians." "Incisive comments." "Icy knifelike reasoning." "As sharp and incisive as the stroke of a fang." "Penetrating insight." "Frequent penetrative observations."

(adj) of an angle; less than 90 degrees. Synonyms: acute (vs. obtuse).

(adj) ending in a sharp point. Synonyms: acuate, sharp, needlelike.

(adj) of critical importance and consequence. Example: "An acute (or critical) lack of research funds."