I never initially like grandma getting tense and resentful (9)
I believe the answer is:
indignant
'resentful' is the definition.
(thesaurus)
'i never initially like grandma getting tense' is the wordplay.
'initially' says to take the initial letters.
'like' becomes 'dig' (I've seen this in another clue).
'grandma' becomes 'nan' (nan can informally mean a grandmother).
'getting' means one lot of letters go next to another.
'tense' becomes 't' (abbreviation used in many dictionaries).
The initial letter of 'never' is 'n'.
'i'+'n'+'dig'+'nan'+'t'='INDIGNANT'
'and' acts as a link.
(Other definitions for indignant that I've seen before include "Annoyed at unfair treatment" , "somewhat angry" , "Taking umbrage" , "feeling anger" , "Affronted by perceived injustice" .)