adjective. Diacritical.

adjective. Diagnostic or distinctive.

noun. A mark, such as the cedilla of façade or the acute accent of resumé, added to a letter to indicate a special phonetic value or distinguish words that are otherwise graphically identical.

Serving to distinguish: same as diacritical (which is the more common form).

noun. A diacritical mark (which see, under diacritical).

adjective. That separates or distinguishes; -- applied to points or marks used to distinguish letters of similar form, or different sounds of the same letter, as, ā, ă, ä, ō, ŏ, etc.

adjective. distinguishing

adjective. Denoting a distinguishing mark applied to a letter or character.

noun. A special mark added to a letter to indicate a different pronunciation, stress, tone, or meaning.

adjective. capable of distinguishing

noun. a mark added to a letter to indicate a special pronunciation