Careful French composer reduced price (10)
I believe the answer is:
deliberate
'careful' is the definition.
(I know that careful can be written as deliberate)
'french composer reduced price' is the wordplay.
'french composer' becomes 'Delibes' (Lo Delibes, 1836-1891).
'reduced' means to remove the last letter.
'price' becomes 'rate' (I've seen this in another clue).
'delibes' with its final letter taken off is 'delibe'.
'delibe'+'rate'='DELIBERATE'
(Other definitions for deliberate that I've seen before include "study" , "Well considered" , "Carefully thought out" , "muse" , "Planned" .)