From the medieval Latin word titulus meaning "small stroke, or accent" we have the English word tittle, which refers to any small distinguishing mark made upon a letter. Notable tittles include the decorative dots that sit atop lower case i and j, and diacritics. But beware the distinction, and for avoidance of the placing of one's foot squarely in one's mouth and general social ostracization repeat after me: A diacritic is a tittle, but not all tittles are diacritics, as an applied diactritic results in a change of the standard pronunciation of a letter.
