Letter or symbol (9)
I believe the answer is:
character
I believe this clue is a double definition.
'letter' is the first definition.
(I've seen this before)
'symbol' is the second definition.
(I know that character is a type of written symbol)
(Other definitions for character that I've seen before include "Letter or number" , "Type - letter" , "Person in a novel or play" , "Distinctive nature" , "crank" .)