Approving of racing driver Hill by end of day (9)
I believe the answer is:
laudatory
'approving' is the definition.
'racing driver hill by end of day' is the wordplay.
'racing driver' becomes 'lauda' (I've seen this before).
'hill' becomes 'tor' (tor is a kind of hill).
'by' says to put letters next to each other.
'end of' indicates one should take the final letters.
The final letter of 'day' is 'y'.
'lauda'+'tor'+'y'='LAUDATORY'
'of' acts as a link.
(Other definitions for laudatory that I've seen before include "Eulogistic" , "puffing" , "Expressing praise and commendation" , "Full of praise" .)