Letter maybe showing integrity (9)
I believe the answer is:
character
I believe this is a double definition.
'letter maybe' is the first definition.
(I know that alphabetic character is a type of character)
'integrity' is the second definition.
(thesaurus)
'showing' acts as a link.
(Other definitions for character that I've seen before include "Eccentric person" , "Sign" , "Person in a play; letter" , "Nature; good reputation" , "Nonconformist" .)