Right to be gripped by joint ambition (5)
I believe the answer is:
'ambition' is the definition.
(I know that ambition can be written as drive)
'right to be gripped by joint' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to be gripped by' means one lot of letters goes inside another.
'joint' becomes 'dive' (I've seen this in another clue).
'r' inserted into 'dive' is 'DRIVE'.
(Other definitions for drive that I've seen before include "Determination, ambition" , "sustained military assault" , "required for excursion" , "Energy and persistence - in car?" , "Force into action, impel" .)