A hacek or háček ("ˇ", pronounced HUH-check), also known as a caron, is a diacritic placed over certain letters to indicate palatalization or jotation in the orthography of some Slavic and Baltic languages.

The word haček means "little hook" in Czech. It looks like an inverted circumflex (^).

The use of hacek (and the acute) for 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, Serbs, Upper Lusatian and Lower Lusatian Sorbs, Lithuanians, Latvians and partly by the Poles. It is also often used for international transliteration.

Examples of letters with the háček/caron:

  • Č/č
  • Š/š
  • Ž/ž


The HACEK organisms are a set of slow-growing Gram negative bacteria that a part of the human normal flora and are a frequent cause of endocarditis in children.

The name is formed from their initials:

  • Haemophilus aphrophilus and Haemophilus paraphrophilus
  • Actinobacillus actinomycetemcomitans
  • Cardiobacterium hominis
  • Eikenella corrodens
  • Kingella kingae