Spouse Catherine who survived grappling with Stanley occasionally (7)
I believe the answer is:
partner
'spouse' is the definition.
(I know that spouse can be written as partner)
'catherine who survived grappling with stanley occasionally' is the wordplay.
'catherine who survived' becomes 'Parr' (Catherine Parr 'survived' Henry VIII).
'grappling with' means one lot of letters goes inside another.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
The alternate letters of 'stanley' are 'tne'.
'parr' placed around 'tne' is 'PARTNER'.
(Other definitions for partner that I've seen before include "teammate" , "Associate, in business or private life" , "Either one of a couple" , "One sharing home or business" , "A person dancing with another" .)