The use of the acute (see also hacek) to denote long pronunciation of Latin characters was introduced by Jan Hus in the 15th century into the Czech language and today it is also used by the Slovaks, Slovenians, Croatians, Upper Lusatian and Lower Lusatian Sorbs, Lithuanians, Latvians, Hungarians, and partly by the Poles. It is also often used for international transliteration.
See also: Acute accent
Acute, in geometry, refers to an angle that is less than ninety degrees (commonly referred to as a right angle).
Acute, in medicine, refers to an intense illness or affliction of abrupt onset. This term refers to timescale of a disease and is often contrasted with subacute and chronic course. Examples: