diacritic
noun
di·a·crit·ic ˌdī-ə-ˈkri-tik 
: a mark near or through an orthographic or phonetic character or combination of characters indicating a phonetic value different from that given the unmarked or otherwise marked element
Example Sentences
Two diacritics appear in the word “déjà vu.”
Recent Examples on the Web The floral patterns at the bottom of the logo as well as the football at the top both reference Qatari culture, while the dots either side of the football are actually Arabic diacritics. 
SI.com, 3 Sep. 2019
SI.com, 3 Sep. 2019 Word History
First Known Use
1866, in the meaning defined above
- changelessness
- changelessnesses
- changeling
- changelings
- changemaker
- changement
- changement de pied
- changements de pied
- changeover
- changeovers
- changer
- changeroom
- changers
- changes
- changes down
- changes of heart
- changes off
- changes one's mind
- changes one's mind (about)
- changes one's mind about
- changeup
- changeups
- changing
- changing bag
- changing box