a diacritical mark (ˇ) placed over a letter in some languages, as Czech and Lithuanian, and in some systems of phonetic transcription, especially to indicate that a sound is palatalized.
1950-55; < Czechháček, diminutive of hák hook < German; see hook
British Dictionary definitions for haček
háček
/ˈhɑːtʃɛk/
noun
1.
a diacritic mark (ˇ) placed over certain letters in order to modify their sounds, esp used in Slavonic languages to indicate various forms of palatal articulation, as in the affricate č and the fricative trill ř used in Czech