di ‧ a ‧ crit ‧ ic /ˌdaɪəˈkrɪtɪk/ BrE AmE noun [countable] technical
[ Date: 1600-1700 ; Language: Greek ; Origin: diakritikos , from krinein 'to separate' ]
a mark placed over, under, or through a letter in some languages, to show that the letter should be pronounced differently from the same letter without a mark
—diacritical adjective :
diacritical marks