Jerk accepting old lady's more badass (7)
I believe the answer is:
tougher
'more badass' is the definition.
(badass can mean tough or formidable)
'jerk accepting old lady's' is the wordplay.
'jerk' becomes 'tug' (synonyms).
'accepting' means one lot of letters goes inside another (inserted letters are accepted).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'lady' becomes 'her' (her refers to a woman).
'tug' placed around 'o' is 'toug'.
'toug'+'her'='TOUGHER'
(Other definitions for tougher that I've seen before include "More tenacious" , "Less tender" , "Stronger" .)