Former partner gets plenty, for instance (7)
I believe the answer is:
example
'instance' is the definition.
('example' can be a synonym of 'instance')
'former partner gets plenty' is the wordplay.
'former partner' becomes 'ex'.
'gets' means one lot of letters go next to another.
'plenty' becomes 'ample' (I've seen this before).
'ex'+'ample'='EXAMPLE'
'for' is the link.
(Other definitions for example that I've seen before include "Specimen, sample" , "Illustrative case" , "Prototype" , "Someone to emulate" , "Standard" .)