A way granny finally shows indifference (6)
I believe the answer is:
apathy
'indifference' is the definition.
(I know that indifference can be written as apathy)
'a way granny finally' is the wordplay.
'way' becomes 'path' (path is a kind of way).
'finally' suggests the final letters.
The final letter of 'granny' is 'y'.
'a'+'path'+'y'='APATHY'
'shows' acts as a link.
(Other definitions for apathy that I've seen before include "Lack of emotion and interest" , "Indifference, emotionlessness" , "Complete lack of interest, indifference" , "Torpor" , "Lack of interest or enthusiasm" .)