Enduring impression finally captured by a French painter (9)
I believe the answer is:
permanent
'enduring' is the definition.
(similar in meaning)
'impression finally captured by a french painter' is the wordplay.
'finally' indicates one should take the final letters.
'captured by' indicates putting letters inside.
'a' becomes 'per' (eg 'one a day' means 'one per day').
'french painter' becomes 'manet' (I've seen this in another clue).
The last letter of 'impression' is 'n'.
'per'+'manet'='permanet'
'n' placed within 'permanet' is 'PERMANENT'.
(Other definitions for permanent that I've seen before include "Unchanging" , "Everlasting" , "that's not changing" , "Lasting, enduring" , "This way for the track" .)