Rough during performance, grabbing old lover (7)
I believe the answer is:
inexact
'rough' is the definition.
('inexact' can be similar in meaning to 'rough')
'during performance grabbing old lover' is the wordplay.
'during' becomes 'in' (I've seen this in other clues).
'performance' becomes 'act' (act is a kind of performance).
'grabbing' is an insertion indicator.
'old lover' becomes 'ex' (I've seen this in other clues).
'in'+'act'='inact'
'inact' placed around 'ex' is 'INEXACT'.
(Other definitions for inexact that I've seen before include "Not precise, approximate" , "estimated?" , "Nice tax (anag) - approximate" , "Not quite right" , "Lax" .)