The term 'Alphabet Character' can be broken down into three separate crossword solutions: RUNE (4 letters), LETTER (6 letters), and ELL (3 letters). RUNE is a LETTER or character of the runic alphabet, which is an ancient Germanic alphabet used for writing various Germanic languages prior to the adoption of the Latin alphabet. LETTER is a written symbol that represents a speech sound and is used in a writing system. ELL is a unit of measurement, usually denoting the length of a line segment from the center of a circle to its circumference.