di·a·crit·ic
noun/ˌdaɪəˈkrɪtɪk/
/ˌdaɪəˈkrɪtɪk/
(linguistics)- a mark such as an accent, placed over, under or through a letter in some languages, to show that the letter should be pronounced in a different way from the same letter without a mark
变音符，附加符号（置于字母上方、下方或穿过字母，表示发音不同） Word Originlate 17th cent.: from Greek diakritikos, from diakrinein ‘distinguish’, from dia- ‘through’ + krinein ‘to separate’.