Meticulous, but imprecise (8)
I believe the answer is:
thorough
'meticulous' is the definition.
(I've seen this before)
'but imprecise' is the wordplay.
'but' becomes 'tho' (I've seen this in other clues).
'imprecise' becomes 'rough' (I've seen this before).
'tho'+'rough'='THOROUGH'
(Other definitions for thorough that I've seen before include "Complete, absolute" , "Miticulous or exhaustive" , "Paying attention to detail, meticulous" , "Passage" , "'Exhaustive, complete (8)'" .)